Let’s cut to the chase. If you’re trying to have a baby, you want to know when you need to have sex. An ovulation test can help predict when you’re most likely to be fertile, and you should take an ovulation test a few days prior to when you anticipate ovulation.

Ovulation takes place in the middle of your menstrual cycle, which begins on the first day of your period. Once your ovaries release an egg, it lives for about 12 to 24 hours. This makes it seem like there’s a small window of time to conceive a baby each month.

However, sperm can live in your body for up to 5 days. So even if you don’t have sex during that 24-hour ovulation window, you may still conceive if you’ve had sex a few days before.

The best time to start testing ovulation is a few days before you’re scheduled to ovulate. Ovulation occurs midway through your menstrual cycle, give or take a few days.

Your most fertile days of the month are 1 to 2 days before and after your ovaries release an egg. Sperm can live in the body for up to 5 days. So, conception can occur if you have sex 5 days before ovulation, and up to 1 day after ovulation.

Predicting ovulation is easier when you have a regular menstrual cycle. With a 28-day cycle, you’ll likely ovulate on or around day 14, so you’ll want to start testing around day 10 or 11.

If you have a short cycle, you can assume that ovulation will most likely occur within 4 days of your cycle’s midpoint. So, you should start using an ovulation test kit 4 to 6 days prior to your cycle’s midpoint.

There’s no wrong or right time of day to test ovulation. Some women prefer to test their urine in the morning, whereas others test it in the afternoon or evening. Whatever time you choose, make sure to test at the same time each day.

Keep in mind that liquid can dilute the amount of luteinizing hormone (LH) in your urine. If this happens, it can appear as if you’re not ovulating when you are. So limit your intake of fluids about 2 hours before testing. It also helps not to urinate 1 to 2 hours before testing.

For the reasons above, many women use ovulation test kits right when they wake up. Testing in the morning also allows you plenty of time to get it on if the test gives you the green light!

Ovulation test kits are more accurate when you have a regular cycle because it’s easier to predict the midway point of your cycle. But don’t worry — ovulation testing can still work if you have an irregular cycle. You’ll just have to test more often.

While women with a regular cycle only need to test ovulation once a month, someone with an irregular cycle will have to test more frequently. You’ll start testing a few days after your period and then once every week thereafter.

Even with an irregular cycle, you can look for the telltale signs of ovulation indicating that it’s time to start using a test kit. You’ll need to pay attention to bodily changes like vaginal discharge and basal body temperature.

Start using an ovulation test kit if you notice any of these symptoms:

Ovulation test strips are designed to detect levels of luteinizing hormone (LH) in your urine. This hormone signals ovulation, which is the release of an egg from your ovaries into the fallopian tube.

While ovulation test strips can determine your most fertile days, they’re not 100 percent accurate. But don’t worry too much — they can have an accuracy rate up to 99 percent, depending on your menstrual cycle.

To test ovulation, you can urinate on the test stick, or urinate in a cup and place the stick in the urine. Results are usually available in about 5 minutes.

Ovulation test kits have two lines: One is the control line that signals the test is working properly while the other is the test line. This line will be lighter or darker than the control line, depending on whether you’re ovulating.

The test line appears lighter when you have a low level of LH in your body. It’ll appear darker when there’s a higher level of LH in your body. This indicates that you’re more likely to conceive.

Find ovulation test kits here.

With such a short window to conceive every month, using an ovulation test kit improves the guesswork of predicting your most fertile days. This information lets you know the best days to have sex for the best chance of conception and can increase your likelihood of getting pregnant.

While ovulation test kits are reliable, remember that they’re not 100 percent accurate. Even so, by documenting your monthly cycles, observing your bodily changes, and testing a few days prior to ovulation, you’ll give yourself the best chance to make your dreams of a baby come true.