Taking a pregnancy test can be undeniably anxiety inducing, whether you’re trying for a baby or not. And while receiving a negative pregnancy test result when you are trying for a baby can be difficult, it’s helpful to keep in mind that not everyone will get pregnant as soon as they start trying to conceive. In fact, recent research suggests the following average timelines for couples under 35, which might be reassuring to know:
- 45% of couples will conceive following three cycles of unprotected sex.
- 65% of couples will conceive following six cycles of unprotected sex.
- 85% of couples will conceive within their first year of having regular unprotected sex.
So if you’re disappointed by a negative pregnancy test, don’t lose hope — try to focus on the potential for conceiving during your next cycle, instead.
You may, however, get a negative result and still think you might be pregnant. Perhaps your period hasn’t arrived, or you think you might be experiencing early pregnancy symptoms. In this scenario, it can be tricky to know what to do and what information to trust (especially if you’ve turned to Dr. Google for advice — we’ve all been there!).
To help explain the science behind both negative and false-negative pregnancy tests, and the best time to do another test if you’re doubting your previous result, we spoke to Dr. Nazaneen Homaifar, obstetrician and gynecologist, Inova Health System, Washington, DC, US. Read on for everything you need to know.
How home pregnancy tests work
Those little home pregnancy tests are pretty clever. They work by checking for a hormone called human chorionic gonadotropin (hCG), which your body only starts to make when you’re pregnant. The volume of hCG in your body (specifically, in your blood and urine) increases rapidly during early pregnancy, doubling every 48 hours between the fourth and sixth week of your pregnancy. If you want to know more, you can track your probable hCG levels at home using our hCG calculator.
Most home pregnancy tests are urine tests. These involve holding a testing stick in your stream of pee or dipping it in a urine sample you’ve collected to test for the presence of hCG. You usually have to wait at least two minutes for the result — which can sometimes feel like the longest 120 seconds of your life. The result will usually show up as one or two lines, a plus or minus sign, or words such as “pregnant” or “not pregnant,” so be sure to read the instructions carefully so you know what to expect. And remember: never use a test that has gone past its expiry date.
How accurate are home pregnancy tests?
If you follow the instructions on your home pregnancy test correctly, then most of them claim to be around 99% effective. However, this might not always be the case, and timing is key to getting the most accurate results — as we’ll discover later on in this article.