Would you like to get pregnant as soon as possible, or are you planning for pregnancy? If so, it helps to know your menstrual cycle well and understand when conception is possible. Our ovulation calculator shows you your fertile days and your most fertile window, when the probability of conceiving is highest.

Why is ovulation important?

Missing ovulation from time to time may not be a problem, but if it happens frequently—or if ovulation stops altogether (and hormones are not taken in any other way)—serious health problems can arise.

The ovulation process provides the body with the necessary levels of estrogen and progesterone , hormones that play a role far beyond fertility. They affect bone density, heart health, metabolism, sleep quality, mental health, and more.

What is the purpose of calculating ovulation?

If you want to have children, knowing the exact day of ovulation can help increase your chances of pregnancy. However, each woman's cycle is unique, and tracking it with a calendar can quickly become confusing, especially if your cycle does not match the "standard" 28 days. The LILLYDOO ovulation calculator helps you easily determine your ovulation and fertile days, and shows you when your chances of getting pregnant are highest.

With the ovulation calculator, you can determine your ovulation and fertile days and narrow down the window when your chances of conceiving are higher. However, the calculations are based on a general pattern and can only provide approximate values.

Your cycle is individual and can always be subject to fluctuations. The calculator is therefore not suitable as a contraceptive if you do not want a pregnancy; it is advisable to consult your doctor about the most suitable contraceptive methods. If you want to become pregnant and your cycle has been very irregular for several months, your doctor can also help you.

However, when you are trying for a baby, the most important thing is not to stress yourself or feel pressured by probabilities and calculations.

How do you know if you are ovulating?

Symptoms and other methods to determine ovulation

Even if the ovulation calculator gives you a good overview of your fertile days, each cycle is individual, so ovulation can sometimes be delayed by one, two, or more days. If your cycle fluctuates a lot, it can be difficult to pinpoint ovulation; if your cycle is stable, ovulation is usually more consistent. There are several signs that can indicate ovulation, especially if you know your body well.

1. Observe the cervical mucus that changes its consistency and color. . During infertile days, it tends to be viscous, sticky, white, and more or less dense. This secretion can vary throughout the menstrual cycle; for example, around ovulation, it becomes thin, clear, and watery. Run a finger over the vaginal opening and insert it up to the cervix to get an idea of the consistency of the cervical mucus.

2. Measure your basal body temperature: Your body temperature, measured immediately after waking, is usually lower before ovulation. Important: to provide reliable values, your wake-up time should always be the same.

3. Use an ovulation test: Test strips measure the concentration of the LH hormone in your urine and are available at the pharmacy. Levels increase significantly just before ovulation.

4. Changes in the cervix: With a little practice, you can feel your cervix to understand which phase of the cycle you are in. Around ovulation, it becomes softer and sits higher in the vagina compared to after ovulation. During infertile days, the cervix is firm and closed.

5. Observe physical symptoms: Some women notice ovulation through symptoms such as abdominal pain, sensitive breasts, or increased desire.

When should you perform an ovulation test?

The test can be performed at any time of day, but it is best to do it at the same time each day.

For an ovulation test kit, it is recommended to choose a time when you have not urinated for 4 hours or consumed an excessive amount of liquids. LH is higher in the morning, between 4 a.m. and 8 a.m. If you perform the test before the hormone peak, you may get a negative result; however, you should still get a positive result the next day.

If you are trying to detect the first surge of LH, or if you are having difficulty getting a positive result, try testing at different times of day and see what works best for your body.

How to increase the chances of pregnancy

Having unprotected sexual intercourse on the day of ovulation does not necessarily mean you will get pregnant. The chance that an egg will be fertilized is about 30% per cycle, assuming both partners are fully fertile. To increase your chances, it is better to have sexual intercourse every two or three days during your fertile days—ideally four and two days before ovulation, and on the day of ovulation.

Good to know: how long are you fertile?

From the beginning of the first menstruation until menopause, usually one ovum—sometimes more—matures in the body each month and is transported to the fallopian tube during ovulation, where it can be fertilized.

However, the egg’s lifespan is limited: it travels through the Fallopian tube for 12 to 24 hours, during which it can be fertilized; after that, it dies .

Fertile sperm, on the other hand, can survive in the female body for up to five days. This means you are not only fertile on the day of ovulation, but also for five days before and up to 12 hours after. So, there are about five days per cycle during which pregnancy is possible.

How to identify your most fertile days?

In adulthood, you are likely ovulating most of the time if your cycle generally falls within the typical range (i.e., 24-38 days for adults, with less than 7-9 days of variation from cycle to cycle and a menstrual period of 2-7 days). Cycles that consistently fall outside these ranges (long, short, or very irregular) may indicate a lack of ovulation (anovulation), so it is advisable to discuss this with your doctor.

Calculate your fertile days

Ovulation is not as precise as a Swiss watch

Many external and internal factors can influence ovulation, for example: environmental factors, energy factors, socioeconomic factors, stress (emotional factors), diet (nutritional factors), seasonal changes, smoking, jet lag, thyroid disorders, PCOS (polycystic ovary syndrome), and changes in physical activity. These can cause ovulation to occur slightly earlier, later, or not at all. Menstruation can also arrive earlier or later, and it may be lighter or heavier. So if the right conditions are not met, ovulation does not occur!

Did you know that the moment you have sex can influence the sex of your baby?

Sperm that carry the female X chromosome survive longer in the female body than male sperm. So, if you have intercourse a few days before ovulation, it is more likely that a female sperm will survive until ovulation and fertilize the egg. If intercourse occurs shortly before or exactly at the time of ovulation, the probability increases that one of the faster male sperm will win the race.

However, it is not possible to influence a child's sex with absolute certainty.