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    When to take a pregnancy test: Top tips for accurate results

    Updated 21 September 2023 |
    Published 06 March 2019
    Fact Checked
    Medically reviewed by Dr. Amanda Kallen, Associate professor of obstetrics, gynecology, and reproductive endocrinology, Yale University School of Medicine, Connecticut, US
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    How soon can you take a pregnancy test? An expert reveals all.

    Getting ready to take a pregnancy test can be exciting, daunting, nerve-racking, and many other emotions all at once. But when exactly is the best time to take a test, and how should you do it? We’ve got all the answers here with helpful input from a Flo expert.

    Key takeaways 

    • For accurate results, take a pregnancy test on the day of a missed period or the day after.
    • The best time to take a test is first thing in the morning.
    • You can use an at-home urine test, or your doctor may offer you a blood test to check for pregnancy.
    • If you get a positive result, reach out to your doctor.


    When can you take a pregnancy test?

    When should I take a pregnancy test? 

    Doing a pregnancy test is pretty easy, right? You pee on a stick, wait a few minutes, and then get your results. However, it’s important to know when to take a test to get the most accurate result. After all, whether you’re trying to get pregnant or not, you want to be able to rely on the pregnancy test you’re taking

    How do pregnancy tests work? 

    The two-week wait — that’s the time between ovulation and your expected period — can be nerve-racking. So, it might help you to understand how pregnancy tests work. 

    Thankfully, they’re pretty straightforward. All home pregnancy tests work by detecting the hormone human chorionic gonadotropin (hCG) in your pee, which the body starts to produce around 6 days after fertilization.

    What hormones do pregnancy tests measure and why? 

    During early pregnancy, your hCG levels will rise rapidly. These rising levels can be detected first in your blood and then in your pee, which is why either can be used to determine whether or not you’re pregnant. During a blood or urine test, you’ll be able to detect whether your body produced any hCG. Your doctor may also analyze your blood test to find out your exact hCG levels.

    Some women’s hCG levels will almost double every 48 to 72 hours for the first eight to 10 weeks. However, it’s worth noting that hCG levels can vary from person to person, and the rate at which they increase can also differ between individuals. So if your doctor tests your exact hCG levels and they aren’t doubling every three days, that doesn’t necessarily mean there’s a problem. Always ask your doctor about any questions or concerns you might have about your levels. 

    Everything you need to know about getting pregnant

    From when to have sex to early signs of pregnancy

    When to take a pregnancy test after a missed period 

    If your period is already due or is late, then now is a good time to take a test. “If your periods are regular, you can take the test on the day of the expected period or the day after the expected period if your period does not occur,” explains Dr. Jenna Flanagan, academic generalist obstetrician and gynecologist, Beth Israel Deaconess Medical Center, Massachusetts, US. “If you have a negative result but do not get your period and still suspect a pregnancy, you can repeat the test in 48 to 72 hours.” 

    If you experience irregular periods or have missed periods in the past, it may be best to wait for 36 days from the start of your last menstrual period before you take a test. Always reach out to your health care provider for more guidance if you feel you need it. 

    Does it make sense to take a pregnancy test before your period? 

    If you’re feeling anxious about whether you might be pregnant or not, it can be tempting to take a pregnancy test immediately. And if you think that would put your mind at ease, then do so — but be mindful that you may not get an accurate result, and you may end up testing again a few days later (unless your period arrives on time). In this instance, it can be especially helpful to have tracked your cycle using an app like Flo to figure out when you might have ovulated and when you might expect your next period. 

    “Typically, it’s advised to wait until you are expecting your next period to take the test because there will be a higher level of hCG at that point, and it’s more likely that the test will be positive [if you are pregnant],” says Dr. Flanagan. 

    If you do take a test early, get a negative result, and then your period doesn’t arrive as expected, you’ll need to take another test. “Take the test again if your expected period does not arrive, usually three to five days after the previous test to ensure the original was not a false negative,” says Dr. Flanagan. If the test is negative but your period still does not arrive, it’s a good idea to reach out to your doctor.

    How soon can you take a pregnancy test after sex?

    Waiting to take a pregnancy test after you’ve had sex can feel frustrating. However, there’s a good reason behind that approximately two-week wait. You need to allow enough time for the embryo to implant in your uterine wall (known as implantation) and for your hCG levels to rise enough to be detectable before you take a test. Otherwise, you may not receive an accurate result. “The pregnancy test will not be positive until the pregnancy has implanted and starts producing hCG in the bloodstream, which can then be detected in the urine,” says Dr. Flanagan. 

    Are you wondering how long it can take to get pregnant after sex? Well, implantation usually occurs about six to 10 days after conception, which means that pregnancy cannot be detected just a few days after having sex. It’s also worth noting that you don’t always conceive immediately after having sex — sometimes, it can take up to five days. Confused? Let us explain.

    When you ovulate, an egg is released from your ovary and makes its way through the tube to your uterus. It stays there for up to 24 hours before breaking down. But if a sperm meets your egg during this period of time, then you’ll conceive. However, it isn’t just during this 24-hour period that sperm can fertilize your egg. If you have sex in the days before you ovulate, some of the sperm could stick around in your reproductive tract (it can survive in there for up to five days, FYI) and could go on to fertilize the egg when it’s eventually released. This is why your fertile window (aka when you are most fertile and the best time to try and get pregnant) not only includes the day of ovulation itself but also the five days beforehand

    With that in mind, you might not be completely sure when exactly your conception sex was. So that’s why the best advice for making sure you’ve left enough time for your pregnancy test to be accurate is to take it either on the first day of your missed period or 21 days after you last had unprotected sex. Tests become more accurate a few days after a missed period, so the longer you can hold out, the better. Don’t forget, you can track your cycle using an app like Flo to monitor when your last period was. 

    How soon can you test after ovulation?

    You might regularly track when you ovulate using an app like Flo and, therefore, have a clear understanding of when you’re likely to ovulate and be in your fertile window each month. You might also have used our ovulation calculator to help you determine when you might have ovulated. But how is this linked to when you can take a pregnancy test? 

    Well, your period is generally expected to arrive around 14 days after ovulation, so if it doesn’t, this could be a good time to take a test. If you’re less sure when you ovulated (which is totally normal, by the way, as it won’t always be exactly the same time each month), it’s a safer bet to be guided by your missed period instead. If you hold out to take your pregnancy test on the first day of your missed period, you can be much more confident it’s going to give you an accurate result.

    When is the best time of day to take a pregnancy test: Morning, afternoon, or night? 

    You might have heard that the best time to take a pregnancy test is first thing in the morning, during your first pee of the day — and there may be a little bit of truth to this. The reason is that it’s possible that your urine could be more concentrated first thing in the morning.

    Dr. Flanagan explains: “Early in the morning, with the first urination, it’s possible that people can be dehydrated, making their urine more concentrated. A test could pick up low levels of hCG that a more diluted sample taken later in the day (after lots of hydration) may miss.”

    However, you don’t need to stress too much about taking a pregnancy test at a specific time of day. Using urine later on when it’s less concentrated may only “hypothetically delay a positive result by only 12 to 24 hours,” advises Dr. Flanagan. 

    When is it too early to take a pregnancy test?

    Now that you know that pregnancy tests rely on detecting hCG in either your pee or your bloodstream, you might find yourself asking how early you can take one for it to be accurate. 

    For traditional at-home urine tests, taking a test more than four days before your next period is due is generally too early, according to Dr. Flanagan. “The pregnancy is not far enough along to have produced enough hCG to detect. Therefore, you risk a false negative,” says Dr. Flanagan. 

    However, some “ultra early” pregnancy tests claim to be more sensitive and are designed to be taken sooner than this. This is because they are specifically designed to pick up lower levels of hCG. For the avoidance of any doubt, however, the best thing to do if you suspect you might be pregnant is to speak to your health care provider. They will be able to talk you through when your last period was and when you last had unprotected sex and may offer you a urine or blood test. 

    Doing a pregnancy test while on birth control 

    You may currently be using a hormonal birth control method like the pill, intrauterine device, or implant and still suspect that you’re pregnant. Even when used correctly, no contraceptive method is 100% effective, so you’re not the only one to have this situation arise. 

    The good thing to note is that if you’re currently taking birth control, it won’t interfere with your pregnancy test results. Dr. Flanagan explains: “Birth control will not affect a pregnancy test as it measures hCG. This is a hormone produced by pregnancy and is unrelated to the estrogen and/or progesterone that’s in birth control.” 

    If you’re currently taking hormonal birth control and think you might be pregnant, it’s worth reaching out to your doctor for advice on what to do next. 

    What are some of the early signs of pregnancy to look out for? 

    Have you felt unusually tired or nauseous lately? You may be considering taking a test because you’ve noticed some of the classic very early signs of pregnancy. Aside from a missed period, some of the most common early signs of pregnancy are: 

    • Peeing more frequently: When you’re pregnant, your body produces more blood. The more blood you have, the more extra waste your kidneys filter out and the more you have to pee. 
    • Fatigue: Feeling extremely tired in early pregnancy is very common, thanks to high levels of the hormone progesterone.
    • Nausea: This symptom can occur as early as two weeks into your pregnancy. You might feel nauseous but never actually vomit, although half of pregnant women do.
    • Sore and swollen breasts: This might feel similar to how your breasts feel before a period. You may also notice that they have gotten bigger.

    What does a false positive mean? 

    A false positive pregnancy test is rare, but it can happen. This is when you get a positive result from a pregnancy test, but you’re not actually pregnant. It can happen if

    • You were pregnant but lost the pregnancy soon after the fertilized egg attached to the uterine lining.
    • You took the pregnancy test soon after taking fertility medicine that contains hCG.

    Remember, if you get a positive at-home pregnancy test result, then it’s always a good idea to book an appointment with your doctor for a checkup.

    What does a false negative mean? 

    As we explored above, it’s best to wait to take a pregnancy test until you are expecting your next period. The risk of taking it sooner is that you may get a false negative even if you are actually pregnant, meaning there simply wasn’t a high enough level of hCG in the urine for the test to detect the pregnancy. In case you weren’t sure, a false negative result is one that tells you you’re not pregnant when, in fact, you are. 

    What are the different types of pregnancy tests? 

    If you’ve checked out this aisle at your local store, you’ll know that the pregnancy test choices are extensive. While there aren’t many differences between at-home test brands, there are two main types of pregnancy tests — blood tests and pee tests. 

    At-home urine test 

    Home urine tests are the way many people find out they’re pregnant. That’s because they’re fairly easy to use and often inexpensive. They involve either peeing directly onto the testing stick or peeing in a container and then dipping the test in. Your at-home test should come with an information pamphlet that outlines how to use it, so it’s always worth giving that a thorough read. 

    Clinical urine test 

    If you visit your doctor when you think you could be pregnant, they may offer you a urine pregnancy test. They will likely ask you to pee in a container so that they can test for hCG themselves. A urine test by your doctor works no differently than an at-home urine test. 

    Blood test 

    The other main type of pregnancy test is a blood test. Again, this works by testing for levels of hCG in the body but via a blood sample. Your doctor will typically be the one to perform a blood test to check for pregnancy.

    A blood test is more sensitive than a urine test and can detect lower levels of hCG, which means they can work a bit earlier than a urine test, around 7 to 10 days after conception. 

    How do I know which test is right for me? 

    The most easily accessible type of pregnancy test is the at-home urine test. If you think you might be pregnant and it’s too early for a urine test, then you can speak to your doctor about accessing a blood test, but these results will be less immediate as you’ll need to wait for them to process your results. 

    It’s also useful to note that while different at-home urine test brands work in the same way, they may display the results differently. For example, some might show two lines when you are pregnant, while others might have a digital screen to display the words “pregnant” or “not pregnant.” Whichever one you use comes down to personal choice; neither is better than the other.

    How long does it usually take before you get results? 

    It usually takes three minutes for an at-home pregnancy test to display your results, but check the packaging to make sure. If your doctor performs a blood test, on the other hand, it will need to be sent off to a laboratory for testing. This means that it will take at least a couple of days before you find out the result of a blood pregnancy test.  

    What not to do before taking a pregnancy test 

    Now that you know when you should ideally take a pregnancy test, you might be curious to know if there’s anything you shouldn’t do in the lead-up to it. You might feel like you’ve not drunk enough water, you may worry you have alcohol in your system, or you might think you need to hold your pee for a while to save it up. But fear not — none of these things really matter. “There’s nothing special to do before taking the test other than reading the instructions and being able to produce enough urine for the test to be accurate,” says Dr. Flanagan.

    Can I trust the accuracy of a pregnancy test? 

    As long as you do the test correctly and at the right time, it’s almost 99% accurate. Despite this, buying an at-home urine test can be confusing, with different brands claiming to be more accurate than others. So, is it true that some tests are more accurate, or is this just marketing? “Depending on the lowest threshold, some tests can detect the hormone in the urine sooner than others,” Dr. Flanagan says. 

    A pregnancy test will appear positive when your hCG levels are at around 50, she explains. For a little bit of context, people who aren’t pregnant tend to have less than five milli-international units of hCG per milliliter (mIU/mL) of blood, but within the first three weeks of pregnancy, levels may rise to anywhere between five and 72 mIU/mL.

    “Some [tests] detect it at 25,” continues Dr. Flanagan. “This is how some brands advertise they are more accurate or can detect a pregnancy sooner.”

    Can medication affect the pregnancy test results? 

    Most medications will not affect the result of a pregnancy test. However, some medications can sometimes cause inaccurate results. 

    H2: What should you do if you test positive with an at-home test? 

    Once you’ve got a positive result, you should call your health care provider to let them know. It’s also a good idea to start following healthy lifestyle habits, like not smoking, drinking alcohol, or having more than 200 mg of caffeine each day. And if you haven’t already, now is a good time to start taking prenatal vitamins, which should include ingredients such as folic acid, vitamin D, and iron.[6] However, it’s always worth checking with your doctor before starting any new medications or supplements while pregnant.  

    When should I see a doctor? 

    When you tell your health care provider that you’ve had a positive result, they’ll make an appointment for your first prenatal checkup. This will usually happen when you are around 8 to 10 weeks pregnant, but how quickly you see a doctor will depend on where you live. 

    During this first visit, your doctor will talk to you about your medical history, lifestyle, and your possible due date. They’ll also perform a physical exam, checking things like your height and weight and possibly performing certain blood tests. 


    Can you detect a pregnancy after 1 week?

    It’s very unlikely you’d be able to detect a pregnancy 1 week after having sex. As we explored above, pregnancy tests detect the hormone hCG once it has passed a certain threshold. And remember, the body only starts producing hCG after conception

    Can too much pee on a pregnancy test make it negative?

    No, but if you check the test too soon or take the test later in the day, it can sometimes cause a false-negative result. Drinking too much water before you take the test can also impact your results. 

    Can an early positive mean twins?

    There is evidence that women carrying twins, triplets, or more produce higher levels of hCG. However, your body would still only start producing hCG after implantation has happened, at 6 to 10 days after conception.


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    History of updates

    Current version (21 September 2023)

    Medically reviewed by Dr. Amanda Kallen, Associate professor of obstetrics, gynecology, and reproductive endocrinology, Yale University School of Medicine, Connecticut, US

    Published (06 March 2019)

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