Ovulation Q & A

Below, find the answers to some of the most frequently asked questions surrounding the topic of ovulation.

When should you start using ovulation tests?

If you have longer or shorter cycles, it can be tricky to figure out when to take an ovulation test.

“I recommend patients start using them daily at around day 10 of their menstrual cycle,” says Zaher Merhi, MD, a reproductive endocrinology and infertility specialist and the founder of Rejuvenating Fertility Center.

What time of day should you take an ovulation test?

Experts agree that when you take an ovulation test doesn’t matter as much as taking them around the same time each day, so you can consistently measure your LH levels over time.

That said, it’s best to use ovulation tests after 11:00 a.m., according to Zitao Liu, MD, PhD, a board certified OB-GYN and fertility doctor. This is when LH levels tend to be highest.

How long after a positive test do you ovulate?

When you get a positive LH test result, ovulation generally occurs in the next 36 hours, Sekhon says, though it could happen as soon as 12 hours.

That means, if you’re trying to get pregnant, you’ll want to time intercourse for the day of or day after your positive LH test result.

Is there anyone who shouldn’t use ovulation tests?

“Ovulation predictor kits aren’t ideal for [those] with very irregular, unpredictable cycles,” Sekhon says. “It’s not very efficient if you need to check every day for months on end. Also, [those living] with polycystic ovary syndrome tend to have high LH levels and may get false positives.”

Similarly, if you’re taking any medications as part of fertility treatments, you shouldn’t use ovulation tests unless instructed by your physician, Merhi says. “Some medications can create false positives.”

Can an ovulation test detect pregnancy?

You might’ve heard that if you don’t have a pregnancy test on hand, an ovulation test can also detect pregnancy because the pregnancy hormone hCG and LH are chemically similar.

While it’s true these hormones have a similar structure, they are significantly different, says Liu. This creates a chance of false positives, so he doesn’t recommend using an ovulation test to check for pregnancy.