1 in 3 cycles may not ovulate. Know if you did.

Whether you ovulated this cycle. After ovulation, your body makes progesterone, then breaks it down into PdG (pregnanediol glucuronide), which shows up in urine. When PdG reaches 5 µg/mL, this test reads positive — a sign that ovulation happened.

Not always. Research suggests more than a third of cycles that look normal may not include ovulation. A regular period is a good sign, but it isn't proof. Confirming ovulation gives you a more complete picture of your cycle.

An OPK tells you ovulation may be coming. This test tells you whether it actually happened. That also means it can't show you your fertile window — for that, use an OPK. You can use both, but you don't need to. This test works on its own, and so does basal body temperature tracking if you already do it.

No. Hormonal birth control (pills, patches, rings, hormonal IUDs), progesterone medication (pills, creams, suppositories) and hormone replacement therapy can all affect PdG levels. Progesterone medication in particular can cause a false positive.

No. This test confirms ovulation after the fact. It isn't a method of contraception and shouldn't be used to decide when sex is 'safe'.

No. It doesn't detect pregnancy, and it isn't meant for tracking PdG during pregnancy. If you think you might be pregnant, take a pregnancy test and talk to your provider.

Take your cycle length and subtract 12. That's your start day, counting day 1 as the first day of your period. For a 28-day cycle, start on day 16. If you use an OPK, start 5 days after your OPK peak instead. If your cycles are irregular, check with your doctor first.

The box has six tests, enough for one full cycle. Test once each morning, at about the same time, until you get a positive.

Yes. First-morning urine has the highest concentration of PdG, so it gives the most accurate reading. Urine from later in the day can give a misleading result.

It is — this test reads opposite to most. One line (Control only) means positive: your PdG is high. Two lines mean negative, even if the Test line is very faint. If you see only a faint greyish Test line with no pink in it, count that as positive. No Control line means the test didn't work; use a new one.

No. PdG takes about five days to build up after ovulation, so a positive means ovulation most likely happened around five days earlier. This test confirms ovulation after it happens, not when it happens.

One cycle isn't a verdict. Some cycles don't include ovulation, and some people don't clear progesterone as PdG at levels high enough to read positive. If you keep getting negatives across several cycles, bring your results to your doctor.

That's fine. Test again the next morning and carry on until you get a positive. One missed day won't undo the picture.

Yes. Alcohol and medications containing natural or synthetic progesterone can affect results. Check the instructions for anything you're taking before you test.

Yes. Hormone levels shift from cycle to cycle with stress, lifestyle and individual factors. Testing across a few cycles gives you a fuller picture than any single one.