When Should I Take a Pregnancy Test for Accurate Results?

Whether it’s a missed birth control pill or the appearance of early pregnancy symptoms, the concern is the same — how long after sex should I take a pregnancy test?

Maybe you’ve searched the internet, downloaded apps to help you calculate your cycle, or even resorted to counting weeks on fingers and double guessing your own math. Millions of women have been there! You are certainly not alone in this.

To know when you should take a pregnancy test for the most accurate results, it’s helpful to begin by first understanding your menstrual cycle.

When am I actually fertile?

Cycles can feel like an irregular mystery. Even women with the most “regular” periods can have questions regarding their cycle. Every woman’s cycle varies, but all women are only susceptible to becoming pregnant for a small window of time,

Cycle Length

The average cycle is 28 days long, but varies for each woman. If you count from the first day of your last period to the day before the first day of your next period, you’ll know your cycle length (to be even more accurate, keep track of your cycle length over a few months and calculate the average). A typical cycle length could average anywhere from 24-38 days apart.

Fertility Window

You can only become pregnant during your fertility window. The key in determining when you are fertile is knowing when you ovulate. Ovulation occurs within your fertility window, a range of days considered “fertile days.” Fertile days are a window within your cycle that your body is in the process of releasing an egg, or the time frame in which a woman can become pregnant.

The time between ovulation and a woman’s next period is typically 7-19 days.¹ Women usually begin the ovulation phase of their cycle a few days after their periods end, but many women, especially those with shorter average cycle lengths, experience an overlap of fertile days at the end of their period. The number of days a woman is actually fertile is about six days per month.²

In other words, yes, it is possible to become pregnant during your period, depending on your cycle length.³

Sperm Survival

In ideal conditions, sperm can live in the female reproductive system for a maximum of five days, so if you had unprotected sex around five days before your fertile window, you may become pregnant.⁴ It’s uncommon to become pregnant that far out from your fertile window, but it does happen.

What is hCG?

Home pregnancy tests can seem like magic; you pee on a stick and receive life-changing information. But a pregnancy test is actually quite simple. It reads the pregnancy hormone Human Chorionic Gonadotropin (hCG) level in your urine, which begins to steadily rise after implantation. HCG is produced by cells formed in the placenta, the organ that nourishes the embryo and is attached to the uterine wall.⁵

An at-home urine pregnancy test will determine whether the hCG levels in your urine have passed a certain threshold, indicating a probable pregnancy. Read your particular test’s instructions for what results indicate a positive test.

How early can I take a pregnancy test?

The most accurate time to test for pregnancy is a week after your missed period, or about three weeks after unprotected sex. There are tests that promise accurate results up to six days before your missed period, but to avoid a false negative, it’s best to wait until the test is more likely to be accurate.

Digital Tests vs. Non-Digital Tests

As someone who has taken about a dozen pregnancy tests and tried different types and brands, I recommend choosing simple pregnancy tests over more expensive digital ones. The first time I bought a pregnancy test, I assumed the more expensive digital tests would render more accurate results. Instead, I actually became more confused.

Digital: Getting results on a screen

One particular time, as I waited for the digital result of “pregnant” or “not pregnant” to show in the test window, I began to doubt. If you’ve never used a digital test before, on the tip of the test that absorbs urine, lines can appear while testing. The instructions warn not to pay attention to these lines, and to focus instead on the words on the screen. But despite the words “not pregnant” I saw in the test window, I was tempted to read into the lines anyway, (as if it was a non-digital test, when “two pink lines” usually indicate pregnancy) and ended up even more confused than before I tested.

This has been my experience, but some women prefer the more “black-and-white” digital result of “pregnant” or “not pregnant” on a screen and aren’t bothered by the appearance of lines on the absorbent tip. If this sounds like you, a digital test will work fine.

Non-Digital: Looking for that second line

After all, there can be drawbacks to non-digital pregnancy tests too, like straining to see if a faint second line has actually appeared after testing. You’ll notice that these pregnancy tests generally use blue or pink dye to show you test results. I highly recommend using tests with pink lines, because they are generally easier to distinguish when looking for a faint test line that indicates pregnancy. Blue lines have a denser “shadow,” so many women find themselves seeing “phantom lines” and buying more tests to clarify.

A woman’s hCG levels increase quickly early in a pregnancy, even doubling within days. Higher hCG levels translate into darker lines on a pregnancy test. Therefore, if you are unsure whether your test is positive or negative, wait a few days and retest. If there still isn’t a darker, obvious second line, your hCG levels probably have not increased, and is good evidence that you are not pregnant.

What time of day should I take a pregnancy test?

It’s best to take your pregnancy test the first time you urinate in the morning. This is when hCG is most concentrated in your urine, before you’ve had the chance to dilute your urine with fluids.⁶

If you miss taking a test in the morning and get a negative result later in the day, it’s still recommended to test again the next morning for best results. Waiting is the hardest part!

What are “false negatives”?

If you are pregnant, but test too early, you can get a false negative result. This means that even though you are pregnant, your hCG levels are still too low to detect.⁷ Waiting can be difficult when you miss your period, but it is critical to getting accurate results. It’s best if you allow yourself to be a week “late” for your normal period for most accurate testing, although you’re likely to get an accurate result any day after your missed period.

What if the pregnancy test is negative?

If you take a pregnancy test and it comes back negative, but you still don’t start your period, consider making an appointment with your OBGYN. You may need a urine or blood test to rule out pregnancy completely, especially if you think you are experiencing early pregnancy symptoms. If you begin your period before the scheduled appointment, you can always cancel. There’s no harm in booking it to gain peace of mind.

Spotting after a missed period

If you have spotting, but not a regular menstrual flow, this may still indicate pregnancy. It’s possible to see spotting, or what seems like a “light” period, that is actually implantation bleeding. Implantation bleeding occurs when an embryo attaches to the uterine wall, causing hormonal changes and light bleeding.

There are several other reasons a woman might see light bleeding after a missed period, so if your normal flow does not return, it may be wise to investigate the cause, even if you’re not pregnant.

If you have irregular cycles

For women with irregular cycles, you may need to continue testing until you see signs of a period or until it’s been far longer than 38 days between cycles. Note: If your cycle continues much longer than 38 days and you are experiencing abnormal symptoms, this is a good time to schedule a check-up with your OBGYN. If you believe you are showing signs of pregnancy but continue to have negative tests, check out our article on negative pregnancy tests after a missed period.

What if the pregnancy test is positive?

If your pregnancy test is positive, schedule an appointment with your doctor as soon as possible to confirm the pregnancy with a blood and/or urine test. Busy OBGYN offices can have long waiting times for patients, so even if you want to wait a few more days to test again yourself, it’s a good idea to reserve your spot on their appointment calendar anyway.

If you are indeed pregnant, check out our other resources listed on this website. We are a community ready to support any woman navigating an unexpected pregnancy.

Scheduling an appointment with your OBGYN is critical after a positive pregnancy test, both for your health and to rule out the rare occurence of a false positive test. Causes of false positives may include: chemical pregnancies (or very early miscarriages), recent miscarriage or abortion, user error, medications, or medical conditions.⁸

Conclusion

Wondering if you’re pregnant can be incredibly stressful. It can be hard not to rush to the store to buy boxes of pregnancy tests, in order to have your answer as soon as possible. But there is a reliable science to determine when a pregnancy test will show you the most accurate result. Such as waiting to test for pregnancy a week after your missed period, or about three weeks after unprotected sex. And testing using first morning urine, when hCG is most concentrated.

If you take an early test, and it comes back negative, test again in the event of a missed period. If an early test comes back positive, schedule an appointment with your doctor as soon as possible to confirm the pregnancy. For more reading:

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