You may have heard that in a typical 28-day menstrual cycle, you release an egg (i.e., ovulate) around day 14. So what if you’ve just started tracking ovulation and find out that the big day happens much earlier than that?
It’s natural to worry when your cycle deviates from the norm, especially if you’re hoping to get pregnant. But early ovulation won’t necessarily harm your chances — we’ll explain why.
“Early ovulation isn’t really a medical diagnosis or term,” explains Flo expert Dr. Jennifer Boyle, obstetrician and gynecologist, Massachusetts General Hospital, US. “However, you could say someone had early ovulation if they ovulated earlier in their cycle than they usually do.”
Since your cycle is pretty unique to you, you might be curious how early you can ovulate. “We think that the earliest day in the cycle when someone can ovulate is on day seven,” says Dr. Boyle. “It just takes that long for an egg to develop and mature before ovulation.”
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Interestingly, there’s a simple reason for early ovulation. It turns out that the first part of your cycle (known as the follicular phase, when your body is getting ready to ovulate) can vary in length from person to person and throughout your lifetime. It all depends on how long it takes for your body to form a fully matured egg.
The second part of your cycle (known as the luteal phase) can last between 10 and 16 days. These two phases are split by ovulation. That’s when one of your ovaries releases an egg in the hope of being fertilized by a sperm. You can learn all about the different phases of your cycle using an app like Flo.
Rather than seeing early ovulation as medical, it’s better to see it as some people ovulate earlier than others. In fact, a cycle as short as 21 days is considered normal. As ovulation usually happens around 14 days before you get your period, this means that you’d expect to ovulate on day seven in a 21-day cycle. So that’s a whole week earlier than the often quoted day 14 — and completely normal.
It can be hard to talk about what’s typical when it comes to our bodies. You might have heard that everyone has a 28-day cycle, but this is a myth. One study found that only 12.4% of women actually have cycles of this length, with most people’s (87%) cycles falling between 23 and 35 days. It totally varies from person to person. Plus, your cycle might vary in length from month to month. However, if you find out that you have ovulated earlier than you usually do, there could be a couple of things going on.
There is some evidence that suggests severe, sudden stress can trigger early ovulation. However, this is quite unusual, according to Dr. Boyle. You’re actually more likely to experience late ovulation or anovulation (when you don’t ovulate at all) when you’re stressed.
“Stress is associated with increased levels of cortisol, which can affect the hypothalamus and the pituitary glands in your brain,” Dr. Boyle explains. “This can cause your reproductive system to pause for a bit. The pause can cause ovulation to be delayed.”
It’s common for your menstrual cycles to get shorter as you age. For example, according to Dr. Boyle, some women find their cycles shorten to around 21 to 24 days during their late reproductive years (the average age a woman stops being fertile is 51). As ovulation happens about 14 days before your period starts, shorter cycles mean a shorter follicular phase and earlier ovulation.
So, what causes these cycle changes? Well, the first thing to know is that the number of eggs you have naturally decreases over time. And, “as the number of eggs in our ovaries decreases, our estrogen levels also decrease,” says Dr. Boyle. Your body needs estrogen to regulate your menstrual cycle, but the hormone also affects things like your heart and blood vessels, bones, breasts, skin, hair, and brain.
“[The drop in estrogen] can cause the pituitary gland to release more follicle-stimulating hormone (FSH),” Dr. Boyle explains. FSH is the hormone that tells the follicles in your ovaries to grow and release an egg. “Higher FSH levels can make ovulation happen earlier in a menstrual cycle,” she adds.
The timing of how egg count decreases varies from person to person, but some people notice their cycles getting shorter in their 40s. Just in case you didn’t know, perimenopause is the time leading up to menopause or your final period. “During this time, menstrual periods will become irregular, and people can have symptoms related to lowering estrogen levels, such as hot flashes and night sweats,” says Dr. Boyle. You can learn all about the symptoms associated with perimenopause using an app like Flo.
Noticing changes to your cycle can be unnerving, especially if you’re hoping to start a family in the future. However, if you think your periods are shortening with age, it doesn’t necessarily mean it’s too late to get pregnant.
If you have concerns about your chances of getting pregnant, don’t hesitate to have a chat with your doctor about it. They’ll be happy to discuss your family goals and help you make a plan.
Since ovulation is such a crucial process in getting pregnant, it’s totally normal to question if changes to when you ovulate will impact your chances. However, this isn’t the case. “Ovulating early should not impact your ability to get pregnant,” says Dr. Boyle.
In fact, one study found that the rate of pregnancy per cycle was around the same among women who ovulated early (defined in the study as before day 13) as everyone else — 20% for those who ovulated early compared to the average rate for all couples which was 21%. This study also found that if you ovulate early, it doesn’t mean you might be less fertile. The earliest ovulation day recorded was on day eight, and that person went on to have a healthy baby from that same cycle.
So, it’s good news if you’re hoping to get pregnant with early ovulation. “It may just take some time to figure out when your fertile days are and make sure that you are having sex before you ovulate,” Dr. Boyle explains. Remember: The Flo app can help you figure out when you’re likely to ovulate by keeping track of where you are in your cycle and teaching you the telltale signs.
"The earliest ovulation day recorded was on day eight, and that person went on to have a healthy baby from that same cycle."
No matter when you tend to release an egg each cycle, tracking the timing of ovulation can help you get to know your body better and learn what’s normal for you. The data will not only help you figure out your fertile window but can help you and your doctor figure out if anything needs further investigation.
“Your cycle should be regular enough that you should have a pretty good idea of the earliest in your cycle that you usually ovulate and the latest,” says Dr. Boyle. “If you are often finding yourself surprised by early ovulation or it seems really unpredictable, then you should probably check in with a health care provider.”
When you’re trying for a baby, having sex around the time of ovulation can boost your chances of getting pregnant. This phase is what’s known as the fertile window, and here’s why it’s so important.
You probably know that in order to conceive, one of your eggs needs to be fertilized by a sperm. In every cycle, the egg you release during ovulation lives for just 12 to 24 hours. During this time, it travels from one of your ovaries to your uterine tube, where it could be fertilized by a sperm. Your chances of getting pregnant are highest when there’s live sperm in your tubes during ovulation.
However, sperm can live for up to five days inside you. So, having sex during the five days before ovulation can lead to pregnancy, as well as during the 24 hours after the egg has been released. This means your fertile window spans six days: the five days before ovulation and one day after. Research suggests that you should have sex every day or every other day during this six-day window to maximize your chances of conceiving.
Using an ovulation-tracking app like Flo can help you figure out when your fertile window will be. Flo’s algorithm can predict when you’re most likely to ovulate and provide personalized recommendations to help you on your trying-to-conceive journey. You can also log any ovulation symptoms in the app, helping you get a full picture of your unique cycle.
If you’re used to premenstrual symptoms just before your period, you might be curious if there are any body signals that you’ve ovulated. The good news is that there are. And, handily, the signs of ovulation are the same no matter when ovulation happens. Here are some ovulation signs to look out for:
You might also notice other symptoms, including:
There are a few ovulation tracking methods you can try. The right one for you will be a personal choice.
You can read more about the following methods in our guide to knowing your most fertile window, but here are the basics. Some people use a combination of two or more methods.
Use the lengths of your previous six menstrual cycles to predict when you’re likely to ovulate.
Log your periods in an app like Flo, and it will predict your fertile window for you.
Just before you ovulate, a sudden rise in luteinizing hormone causes you to release the egg. Detect the surge by measuring the level of the hormone in your pee.
Your BBT rises very slightly after ovulation — take your temperature every morning to find out when this tends to happen.
Keep a note of changes in your vaginal discharge so you can spot when your fertile cervical mucus arrives.
As well as helping you track ovulation symptoms, you can use the Flo app to log your BBT and ovulation test results. Whichever method or combination of methods you use, apps like Flo can help you keep your symptoms information and fertile window dates all in one place.
The earliest possible ovulation day is seven days after your period starts, according to Dr. Boyle. This is because it takes your body around seven days to produce and mature an egg for ovulation.
If your cycles are always around 21 days long, ovulating as early as day seven is perfectly normal. It’s natural to experience slight variations in your cycle. However, if this happens often or your cycle becomes unpredictable, it’s a good idea to reach out to your doctor.
“A woman can release two eggs during ovulation, which can lead to nonidentical twins,” says Dr. Boyle. “But there cannot be two separate ovulation events within the same menstrual cycle.”
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Understand what your symptoms might mean — and what's normal for you — by tracking your cycle.
Follow your baby's growth and see how your body is changing.
Know when you're most fertile to maximize your chances of getting pregnant.
