Planning a pregnancy? Then it’s worth planning the preparation too—and you can take that quite literally. Because babies don’t come from storks, it helps to look at the calendar and get familiar with the menstrual cycle. You can’t get pregnant 365 days a year—only around ovulation. And you can calculate those fertile days. How? You’ll find out below.

Do you want to calculate your ovulation now? Then scroll down and use our handy ovulation calculator . It shows you right away when your chance of pregnancy is highest.

Why calculate ovulation?

Every menstrual cycle prepares a woman's body for pregnancy. If you wish to have children, it’s important to know the exact day when ovulation occurs. This increases the chance of becoming pregnant. But when exactly does ovulation happen? On average, it’s about every 28 days, but a cycle is as individual as a fingerprint —and it can be even more complicated: ovulation may occur earlier or be delayed. LILLYDOO offers you a handy tool to calculate ovulation. This way, you can quickly see when your chance of conceiving is highest.

Calculating ovulation: here's how it works

Ovulation usually occurs 14 days before the first day of the next menstruation , and the timing of ovulation correlates directly with the length of your cycle in days. If your cycle lasts, for example, 30 days, then ovulation occurs approximately 16 days after the start of your last period.

The cycle varies from woman to woman , but it usually lasts between 25 and 32 days . So if you have a shorter cycle, ovulation occurs earlier; with a longer cycle, it occurs later—typically between day 11 and day 18, counting from the first day of menstruation.

Don’t worry—you don’t have to remember all of this exactly, because our handy ovulation calculator will do the calculations for you. What you do need to note is:

• the first day of your last menstrual period (also known as the day the bleeding started)

• the average length of your cycle

Once you’ve entered those numbers, the tool starts calculating. The result includes everything you need to know on the way to a positive pregnancy test: when ovulation occurs (estimated), your fertile days, the day implantation may take place, and when you might see that line on a pregnancy test.

When is ovulation? Calculate it now

Ovulation symptoms and more ways to calculate ovulation

Did you use the ovulation calculator above? Then you now have a clear overview of your fertility. But every cycle is different, and ovulation can easily occur one to two days later .

When your cycle varies greatly, calculating ovulation can be quite difficult. If your cycle is stable, ovulation is usually consistent. There are also other methods to determine when ovulation occurs. These require some knowledge of the body, and you’ll need to be able to recognize the symptoms of ovulation :

• Check the mucus from the cervix. In your cervix there is mucus, the so-called cervical mucus. This varies in color and consistency throughout a cycle. In the first week after menstruation, the mucus is thick and sticky. This keeps the cervix closed against external influences. As ovulation approaches, the cervical mucus becomes transparent and elastic. You can then pull threads of it with your fingers. After ovulation, the mucus becomes opaque again, loses its elasticity, and can sometimes be a bit grainy. A few days before your period, your vagina may feel dry. Recognizing and observing this pattern can help determine your cycle (and thus your fertile period).

• Measure the basal body temperature. Basal body temperature is your body temperature immediately after waking up. Before ovulation, it is lower than afterward (by a few tenths of a degree). Note: to calculate ovulation accurately with this method, you should measure your temperature at the same time each day.

• Buy an ovulation test. With this test, which you can easily obtain at the pharmacy, you can see when you are most fertile. Especially with an irregular cycle, an ovulation test can provide more certainty.

• Check the cervix. It takes some practice, but by feeling the cervix, you can check the phase of your cycle. As ovulation approaches, it becomes soft and sits higher in the vagina than before. During the infertile period, the cervix is firm and closed; the chance of pregnancy is then minimal.

• Keep a close eye on your body. Some women notice ovulation through symptoms such as abdominal pain, tender breasts, or increased libido.

How to increase your chances of getting pregnant

The egg is released, the ovaries get to work, and the condom stays in the nightstand. Time to head between the sheets! Still, sex at the key moment doesn’t necessarily result in a baby. The chance that an egg is actually fertilized is about 30 percent per cycle . So if you want to increase your chances, it helps to make it cozy in the bedroom. Feel free to have sex daily or every third day—ideally four and two days before ovulation, and on the day of ovulation itself.

How long is a woman fertile (and do eggs stay alive in the body)

From the first menstruation until menopause, usually one egg matures each month—and sometimes even more than one—and ends up in the fallopian tube. There, it can be fertilized.

The egg cell doesn't last very long, by the way. . Over a period of 12 to 24 hours, it makes its way through the fallopian tube. If no gallant sperm cell shows up, the fun is over and the egg dies. The dead egg is transported out of the body via the menstrual flow.

Why do we recommend having sex on multiple consecutive days above? Because a sperm cell can survive on average three but sometimes up to five days in a woman's body . This means that there is not only a chance of fertilization during ovulation, but also roughly five days beforehand and an average of 12 hours afterward. Moreover, these swimmers aren’t slowpokes: the faster a sperm cell moves through the female body, the greater the chance of fertilization.

With the ovulation calculator, you can quickly estimate your ovulation and identify your fertile days. This can increase your chances of pregnancy. Keep in mind that the ovulation calculation is based on a general pattern, and all results are guidelines. Cycles vary from woman to woman and can also differ from month to month. Therefore, do not use the calculator as a method of contraception.

If you do not want to become pregnant, be sure to ask your doctor about suitable contraception. And if you’re planning a pregnancy but your cycle is very irregular, your doctor can certainly help you further.

And finally, the most important thing: if you want children, try not to focus solely on probabilities, calculations, and a script that would make a wedding planner fall backward. In short: don’t put pressure on yourself. Instead, let nature guide you and trust your own body.

Frequently Asked Questions