It’s a handy tool to help you work out the most fertile time in your cycle, but can an ovulation test detect pregnancy, too?
Medically reviewed by Navya Muralidhar, embryologist and educator.
A pregnancy test does, well, just what you expect it to!
And an ovulation test can give you important clues as to when the most fertile time in your cycle is.
But does this type of test have hidden talents?
Specifically, can an ovulation test detect pregnancy, as well as predict ovulation?
We’ve got the answers here.
In this article: 📝
- Ovulation test vs. pregnancy test: what’s the difference?
- Is an ovulation test positive if you’re pregnant?
- How can ovulation test detect pregnancy?
- Can an ovulation test detect early pregnancy?
- When is the best time to get ovulation test?
Ovulation test vs. pregnancy test: what’s the difference?
First, though, let’s take a spin around the basics.
The main difference between an ovulation test and a pregnancy test is the hormone they measure:
Also known as an ovulation predictor kit (OPK), an ovulation test measures levels of the luteinizing hormone (LH) in your urine.
LH is the hormone sent from your brain to your ovaries with the message: Release the egg!
So, a positive result on your ovulation test means that you’re likely to ovulate in the next day or so.
Armed with that info, you can then time sex or fertility treatments, such as IUI, to maximize your chances of getting pregnant.
A home pregnancy test measures a different hormone in your urine—human chorionic gonadotropin (hCG).
HCG is the hormone made by the cells surrounding a new embryo, which will eventually become the placenta (your baby’s life-support system in the uterus).
So if the test detects hCG, you’ll get a positive pregnancy test result.
Some early pregnancy tests can detect hCG up to five days before your next expected period.
But for a standard test, it’s recommended to wait until at least the day your period is scheduled to come.
Say, though, you’ve run out of pregnancy tests, but you’ve got stacks of ovulation tests—could you use an ovulation test to test for pregnancy instead?
Is an ovulation test positive if you’re pregnant?
Strangely enough, an ovulation test might be able to detect pregnancy.
If you take an ovulation test around the time you would normally take a pregnancy test and you get a positive result, that could mean you’re really pregnant.
But it’s not a surefire thing.
We’ll dive in deeper below.
How can ovulation test detect pregnancy?
Basically, even though they have very different jobs to do in your body, LH and hCG have similar molecular structures.
And this similarity can “trick” some ovulation tests into giving a positive result if they detect hCG rather than LH.
That means you could take an ovulation test in the early stages of pregnancy and test positive.
And that’s because the test is picking up the wrong hormone.
But here’s the thing.
An ovulation test isn’t designed to be used to detect pregnancy.
And there are a couple of good reasons not to use them for this purpose:
- Ovulation tests aren’t as sensitive as pregnancy tests: There’s a good chance they won’t pick up on hCG early in pregnancy when levels of the hormone are still low. So you could get a negative result on an ovulation test and still be pregnant.
- You can’t tell whether the test is picking up hCG or LH: If you want to use an ovulation test to check for pregnancy but test too early in your cycle, the test could detect LH rather than hCG. And you might then think you’re pregnant when you’re actually about to ovulate!
Can an ovulation test detect early pregnancy?
The two-week wait (TWW) can feel like an eternity, we know.
It’s totally understandable that you want to take a pregnancy test ASAP.
So could taking an ovulation test (as a pregnancy test) get you that positive result sooner?
Probably not, unfortunately.
As we explored, ovulation tests just aren’t as sensitive as pregnancy tests, so they might not detect any hCG early on.
Instead, you could try taking an early pregnancy test, which can detect pregnancy up to five days before your expected period.
And then test again a few days later if need be.
When is the best time to get ovulation test?
Timing is everything when it comes to TTC, and it’s not just when it comes to knowing when to have sex.
You’re at your most fertile one to two days before your ovaries release the egg so nailing the timing is essential.
This is why an ovulation test can be your greatest asset for scheduling baby-making time in that critical 24-hour ovulation window.
As ovulation happens midway through your menstrual cycle – think around day 14 – you’ll want to start testing about three or four days beforehand.
As for the hour of the day? There is no wrong time, but many women tend to favor the first urine of the day (that’s FMU in TTC language).
Now recent fertility studies have shown that between 12pm and 6pm is the prime time for LH to surge so that FMU may fast become an NP (noon pee).
In any case, keep in mind fluids can dilute the amount of LH in your pee so if you can’t test until later in the day, keep tea and water to a minimum.
How do I know I’m ovulating?
Look, not every woman is the same, and no menstrual cycle was created equal.
If you do have irregular periods, you may need to take a couple of ovulation tests before you find the sweet spot.
And don’t worry, sperm is surprisingly hardy and can live in the body for up to five days.
Even if you miss your 24-hour window, you still have an entire fertility window for conception to happen.
Yes, even if you had sex five days before ovulation.
Essentially, both ovulation tests and pregnancy tests are handy tools to have in your TTC toolbox, but it’s best to use them for the purposes they were intended for.
If in doubt, check in with the TTC community on Peanut.
We’re rooting for you. ❤️