How to use a pregnancy test strip

You can test up to 5 days before your missed period. That said, hCG levels are still low at that point and vary from person to person, so an early negative doesn't mean you're not pregnant. If you test early and see a negative, wait 48 hours and try again with first-morning urine. The test is over 99% accurate from the day your period is due, when used as directed.

Morning is best, particularly if you're testing before your missed period. hCG builds up in your bladder overnight, so first-morning urine is the most concentrated sample you'll get all day. After your period is late, time of day matters less, just avoid drinking a lot of fluid right before testing.

You can. If you're past your missed period, hCG is usually high enough that it won't matter. But if you're testing early, a nighttime sample may be too dilute to pick up low hCG levels. Try to hold your urine for at least 3-4 hours and limit fluids beforehand.

Not for at least 12-14 days. After fertilization, the embryo takes about 6-12 days to implant. Only after implantation does hCG production begin, and it needs a few more days to reach a detectable level. If you're not tracking ovulation, wait at least 19 days after unprotected sex or just test when your period is due.

Test at least 19 days after the last time you had unprotected sex. If the result is negative and your period still hasn't shown up a week later, test again or see your healthcare provider.

A colored line in the test area within 5 minutes, no matter how faint, means hCG was detected. The test is positive. Contact your healthcare provider to schedule next steps. It's worth knowing: a positive result followed by early pregnancy loss (chemical pregnancy) does happen, and it is not uncommon.

Either you're not pregnant, or hCG hasn't built up enough to detect yet. If you tested early or your period still hasn't started, test again in 48 hours. In early pregnancy, hCG roughly doubles every 2–3 days, so a negative today can become a positive a couple of days later. If negatives continue and your period stays late, talk to your doctor.

Yes. A faint colored line means hCG was detected at a lower level, which is typical when testing early. If you want to see the line get darker, retest in 48 hours. But line darkness is not a reliable way to track how far along you are — the test gives you a yes or no, not a measurement.

Yes, especially if you tested before your missed period. hCG doubles roughly every 48–72 hours. A test that's negative at 10 days past ovulation can show a clear positive by day 12 or 13. If your period hasn't arrived, retest in 48 hours with first-morning urine.

No. Differences in dye lots, urine concentration, and testing conditions all affect how lines appear. Don't compare strips from different days or different batches to gauge your hCG level. If you want actual numbers, your doctor can order a blood test.

No. Read at 5 minutes, then discard. After the testing window, evaporation can leave marks on the strip that look like a faint line but aren't real results.

The test didn't run properly. Usually this means the strip wasn't dipped deep enough or was dipped past the MAX line. Repeat with a new strip, dipping up to the MAX line for the full 5 seconds.

Rarely. If a line appears, hCG was detected. But hCG can be in your system for reasons other than an ongoing pregnancy. A recent miscarriage or delivery (hCG can linger for 6–8 weeks), a chemical pregnancy, or fertility medications containing hCG like trigger shots can all cause a positive. Most common medications — antibiotics, painkillers, birth control, Plan B — do not cause false positives.

More common than a false positive. The usual reason is testing too early, before hCG reached 25 mIU/mL. Diluted urine (from drinking a lot of fluid) is another common cause. If negative but no period, retest in 48 hours with first-morning urine.

Probably not yet. Implantation bleeding happens around 6-12 days after ovulation, right when your body is just starting to produce hCG. At that point levels are usually too low for a home test. If you notice light pink or brown spotting that doesn't look like your usual period, wait until the day your period is due and test then. A negative during what you think is implantation bleeding doesn't rule anything out.

This may be an early pregnancy loss, sometimes called a chemical pregnancy. This can happen when hCG rises briefly in a very early pregnancy that does not continue. In most cases it doesn't affect future fertility. If this happens, your healthcare provider can talk you through it.

If your treatment included an hCG trigger shot, leftover hCG from the injection can give you a false positive. Follow your clinic's instructions — they'll typically tell you to wait 10–14 days after the shot before testing at home.

Over 99% accurate from the day of your expected period, when used as directed. Earlier than that, accuracy depends on where your hCG level is. The test detects hCG at 25 mIU/mL.

The strip has antibodies that bind to hCG. When you dip it in urine, the sample travels up the strip. If hCG is at or above 25 mIU/mL, a colored test line appears alongside the control line within 5 minutes.

Yes, though heavy bleeding can make the strip harder to read. If you're unsure about the result, retest in 48 hours with a clean sample.