This is a question that intrigues many women who are trying to get pregnant, isn’t it? Knowing when to take a pregnancy test is a tough dilemma, especially if you have been trying to conceive for a long time or have received many negatives before. The big problem lies in taking the test too early, even before having a significant menstrual delay so that the HCG hormone is produced and detected by a standard 25mUI sensitivity test (the measurement unit for the HCG hormone exclusive to pregnancy).

Let’s start from the beginning. Even when a woman has intercourse with her partner without any contraceptive or when using some conception aid, it is still necessary to be in the fertile window to get pregnant, right? This fertile period varies from woman to woman according to her menstrual cycle, whether regular or irregular. In fact, to detect the fertile window and track the cycle and ovulation more closely, ovulation tests are great! They show if ovulation is approaching, if it’s happening, or if it has already ended, which is a big help for those trying to conceive. You can learn about Famivita’s ovulation test here.

When Does Pregnancy Actually Happen?

You only get pregnant during the fertile period, and after that, it can take a while for pregnancy to appear—about 12 to 15 days after intercourse. That’s because, after fertilization, the embryo can take 7 to 15 days to reach the uterus and attach to the endometrium, known as implantation1. So, the question arises: how many days after implantation does the test turn positive? Many women test too soon, that is, before this 7 to 15 day period and get upset by a false negative or with “a wrong test“, when the positive could appear just a few days later. To get accurate results, it is necessary to wait for the presence of HCG, which only starts appearing after the embryo implants in the uterus.

When Should You Take the Test to Avoid a False Negative?

You need to wait for the proper time according to your cycle to start testing, meaning, know when you ovulated before taking the pregnancy test2, whether it’s a pharmacy test or a blood test. Normally, a test can start to show positive at 13 or 15 dpo (days past ovulation), and even then, it can be quite faint. In irregular cycles, knowing when to take a pregnancy test is trickier, but if you have learned to detect your ovulation, even with irregular cycles you are already ahead!

Theoretically, you would be the same as women who have regular cycles, and that’s already halfway there. Now, if you don’t know when you ovulated, for a more accurate test you’ll need to wait 20 to 30 days after the risky intercourse to know if pregnancy happened or not, avoiding a wrong test.

IMPORTANT: anxiety can be the biggest enemy for women trying to conceive. Besides interfering with conception, it leads to testing before the right time, causing frustration.

Which Is the Best Pregnancy Test?

Pharmacy tests are getting more and more sensitive. However, the best to detect any amount of HCG in the blood is the quantitative beta HCG, as it can identify even minute amounts as low as 0.1 of HCG in a woman’s body. Of course, the lab’s reference is important to determine if the result is positive or not, but usually, values above 25mUI of HCG are already considered positive.

Generally, values below 5mUI are considered negative, as a woman may have this amount of HCG in her body just from fertilization. According to recent studies, during fertilization a minimal amount of HCG is released, which would explain hormone values below 4mUI. Values above 5mUI indicate an indeterminate result, meaning it is too low to be positive and too high for a negative. Now, values like 6, 7 or 10mUI are strong candidates for progressing positively to pregnancy. To know if there is progression, just repeat the test after 48 hours and check the value, which should double in the case of a positive result.

Regarding the pharmacy pregnancy test, the right time to take it is a bit more delicate. Depending on the test’s sensitivity, a very faint second line may appear and, even so, be considered positive with a short time since implantation (implantation). Tests with 10mUI sensitivity are the best to use as soon as a woman notices a missed period, such as the Famivita pregnancy test, which due to its high sensitivity, can detect HCG levels up to 5 days before a missed period. You can find the Famivita pregnancy test here.

There is some evidence that ovulation tests that detect LH in urine may also pick up an early pregnancy, because the LH hormone structure is very similar to that of the pregnancy hormone. So, if you are curious, you have that option as well.

False Negative After Missed Period

Sometimes, the test may come back negative even after a missed period, and only after a few considerable days of delay does the HCG finally show up. This happens fairly often3, because some women ovulate after the expected date, and then the pregnancy hormone may take longer to appear in urine or blood. This type of ovulation is known as late ovulation.

In summary: it is very important to know the exact moment to take the test, because taking the test before a missed period can result in a false negative because implantation — that is, actual pregnancy — may not have happened yet. There are a whole set of factors that must line up for pregnancy to occur, and anxiety and impatience have a direct effect on a frustrating and unnecessary false negative. Therefore, waiting at least 5 days after a missed period is always the most advisable.

Positive Before Missed Period

You might be wondering: “But my friend/sister-in-law/sister got a positive even before her period was late. How is that?” Some women have the advantage of ovulating earlier in a given cycle and then everything happens sooner, including implantation and hormone production. This makes it much easier to detect pregnancy before a missed period. When in doubt, we recommend waiting until your period is late to avoid a frustrating negative that can hurt your hopes even more.

Reader Questions:

How long after implantation should I take a pregnancy test?

Ideally, it is best and most advisable to take a pregnancy test only after a missed period, avoiding unnecessary frustration and even false negatives due to low levels of HCG in the blood.

It’s been a month since I had intercourse, when can I take a pregnancy test?

To avoid frustration, a pregnancy test should only be done when there is a sign or doubt, such as a missed period or specific symptoms like nausea, dizziness, and breast tenderness. If your period is late, you can take the test on the very first day of the delay.

I didn’t get my period, and I’m only getting brown discharge. Should I take a pregnancy test?

Brown discharge or “coffee grounds” periods are not necessarily a sign of pregnancy, as they can result from hormonal fluctuations, implantation bleeding, the start of menstruation, or even the effects of medications like the morning after pill.

See you next time and hang in there!

See also: Positive Pharmacy Test and Negative Blood Test! Now What?