Can I take a pregnancy test at night?

You can, but results may be less reliable if you've been drinking fluids throughout the day. Nighttime urine is often more diluted than first morning urine. For the most accurate results, especially in early testing, use your first morning urine before drinking anything.

How long should I wait before retesting after a negative?

If you test before your missed period and get a negative, wait until the first day of your missed period to retest. If you test on the day of your missed period and get a negative, wait 2–3 more days before retesting, as hCG levels double rapidly and a borderline result may become clearly positive within days.

Which pregnancy test can detect the earliest?

First Response Early Result (FRER) is consistently rated as the most sensitive home pregnancy test, with a detection threshold of approximately 6.3 mIU/mL. This makes it capable of detecting pregnancy earlier than most other tests.

When to Take a Pregnancy Test for the Most Accurate Result

The Science Behind Pregnancy Test Timing

Home pregnancy tests detect human chorionic gonadotropin (hCG), a hormone produced by the developing placenta after a fertilized egg implants in the uterus. Implantation typically occurs 6–12 days after ovulation. Once implantation happens, hCG production begins and levels double roughly every 48–72 hours.

The key challenge is that in the very earliest days after implantation, hCG levels are often too low for a standard home test to detect. Most tests have a detection threshold of 20–25 mIU/mL. At 7–8 DPO (days past ovulation), hCG may be as low as 2–10 mIU/mL - below what most tests can find.

The Best Day to Take a Pregnancy Test

For the most reliable result, wait until the day of your expected period (or the day after a missed period). At this point, hCG levels in a confirmed pregnancy are typically 50–200 mIU/mL - well above the threshold of virtually all home tests.

Testing on the day of your missed period gives you the highest probability of getting an accurate result without testing unnecessarily early. If you test before this point and get a negative, you cannot rule out pregnancy with confidence.

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Testing Before Your Missed Period

Some tests are marketed as able to detect pregnancy 5–6 days before a missed period. The most sensitive option is First Response Early Result (FRER), which can detect hCG as low as 6.3 mIU/mL.

However, even with the most sensitive tests, early testing has real limitations. hCG levels at 9–10 DPO vary widely between individuals, and many pregnancies will not yet produce enough hCG to be detected. A negative result before your missed period should be followed by a retest on the day of the missed period.

Why First Morning Urine Gives the Best Results

Your first morning urine (FMU) is the most concentrated urine of the day. During sleep, you go several hours without drinking fluids, which allows hCG to accumulate in your urine at higher concentrations.

Testing with FMU - before drinking anything or urinating - maximizes the hCG concentration in the sample and gives the test its best chance of detecting low levels. This is especially important in early testing, where hCG levels are borderline.

How Test Sensitivity Affects Your Timing

Different brands have different detection thresholds. More sensitive tests can detect pregnancy earlier, while less sensitive ones require higher hCG levels. Knowing your test's sensitivity can help you calibrate expectations.

First Response Early Result: ~6.3 mIU/mL (most sensitive)
Clearblue Digital: ~25 mIU/mL
Wondfo/Easy@Home strips: ~25 mIU/mL
Dollar store tests: ~25 mIU/mL