Common questions about ovulation tests

ovulation test questions

Every cycle is different, so when it comes to tracking ovulation, it isn’t always black or white. In fact, taking an ovulation test can be so confusing that a lot of people avoid it completely. But trust us, once you know how beneficial it is to track your cycle, you’ll want to know exactly how ovulation testing works and what the results mean.

To save you time and patience reading the long, 6 point font instructions that come with most store bought OPKs (ovulation predictor kits), we’ve answered all the questions you didn’t even know you had regarding ovulation testing.

How do ovulation tests work?

Let’s start with the basics. Ovulation tests work by measuring a hormone called luteinizing hormone (LH) in your urine. LH sends a signal from your brain telling your ovaries when it is time to ovulate. When levels of LH are high, it’s likely that you’ll ovulate between 16 and 48 hours after taking the test. This is known as an LH surge and is what you’re looking for in the results of your ovulation test.

What do my ovulation test results mean?

Although ovulation tests look a lot like pregnancy tests, they serve very different purposes. Every ovulation test is different, but they generally come with 5-10 sticks and have similar instructions.

Like a pregnancy test, each ovulation test has two windows. One window will show a line indicating that the test is working properly. This is known as the control line. The second window will tell you if your LH levels are high and you are likely to ovulate soon, this is known as the test window.

If the line in the test window is as dark or darker than the control line, it means your LH is surging and ovulation is coming around the corner.

When should I take ovulation tests?

It’s best to take ovulation tests first thing in the morning, or as many hours since your last fluid intake as possible. This is because drinking excessive fluid before urinating on the test will dilute your LH concentration and make it harder to detect ovulation.

On average, an LH surge lasts for 2 days, but every woman’s LH surge is different. So, you might want to test twice the day of an LH surge to get a better idea of when it started and how long it might last. If your ovulation test indicates you are having a surge, it’s likely that you’ll ovulate within the next 48 hours of that positive ovulation test.

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How should I plan sex around ovulation?

Let’s talk about the fun part of ovulation: sex! Knowing when you're ovulating is essential for planning sex, especially if you're trying to get pregnant. Yet another confusing aspect about ovulation testing is that you should not wait to have sex until you get a positive test result.

Your body is actually the most fertile 2-3 days before ovulation. In other words, you’re less likely to get pregnant if you wait for a positive test result than if you had sex a few days before. Very calculated, we know. That’s why we recommend taking tests more frequently than you think is necessary.

How do I calculate when ovulation is likely?

It’s time to address the elephant in the room: how can I predict when I’m most likely to get a positive result? It’s a science. Ovulation typically begins about 14 days before your period starts.

Depending on how long your cycle typically is, you can get a rough estimate of when you will ovulate by finding the 14th day of your cycle, as your menstrual cycle ends the day before your next period. To measure your cycle length, count the amount of days between the first day of your last period period and the first day of your next one.

This becomes a loaded question for women like us who have irregular cycles. Yet another inconvenience of having an irregular period is having a difficult time predicting ovulation. Keeping close track of ovulation is especially important with an unpredictable cycle, as it will be harder to catch your ovulation window. If this sounds like you, we recommend loading up on ovulation tests daily to ensure you don’t miss it.

Can an ovulation test show a negative even if I'm ovulating?

Along with pregnancy tests, it is possible to get a negative result on your ovulation test when you are in fact ovulating. One thing you can do to avoid getting a false-negative test result is to be sure you are testing early or late enough in your cycle. We like to test every day in the morning starting 10 days after our cycle starts.

It’s important to remember that ovulation tests detect the LH hormone, not ovulation itself, and there is only a certain amount of time that the surge will show up in your urine. Think of the LH surge as a warning that you’re about to ovulate. If you don’t catch the surge while it’s happening, your test results will be negative and you will think you’re not ovulating when you actually are.

Fortunately, tracking your ovulation is much more simple than it seems. Here at Stix, our mission is to provide everyone with the clarity and convenience they deserve.

Still confused by ovulation testing? Ask us anything at

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