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Ovulation calendar – calculate when you are ovulating


With our ovulation calendar, you can easily calculate when you are ovulating and your most fertile days. It is a practical tool for those trying to get pregnant and who want to know the days when they have the greatest chance of getting pregnant. An egg can be fertilized for a maximum of 24 hours, but sperm usually live for several days. Therefore, it can be good to have intercourse / introduce sperm 2-3 days before ovulation, up to 1-2 days after.

Ovulation calendar

Here you can find out your ovulation date and the days on which you have the best chance of getting pregnant during intercourse. The dates in the calendar are approximate and may differ from reality, especially if you have an irregular menstrual cycle.

You have the highest chance to get pregnant

  • Menstruation
  • Ovulation (highest chance of getting pregnant)
  • Fertile days (chance of getting pregnant)

Ovulation: more about how you calculate when you are ovulating

You can calculate approximately when ovulation will occur, based on your first menstrual day. You can do this quickly and easily via the ovulation calendar above. Ovulation usually occurs 14 days before the next period. If you have an irregular menstruation cycle you can enter both the longest and the shortest menstrual cycle to see how the calculated fertile days vary.

The time from ovulation to the next period  does not actually vary much between women. It usually lasts 14 days. But the time from the first day of your period to ovulation can vary quite a bit! This is because the total length of the menstrual cycle can vary between 25-32 days for women.

Example: if you have a regular menstrual cycle that is 25 days long, ovulation will occur around day 11. But if your menstrual cycle is 30 days long, ovulation will not occur until around day 16.



How do I know I am ovulating?

Some people know when they are ovulating. They get, for example, pain in the lower abdomen and sometimes a little bleeding. But these symptoms are not completely sure signs. To know exactly, neither symptoms nor calculating a probable date of ovulation are enough. You can use an ovulation test that shows when LH hormone is present in the urine, which is a sign that ovulation is close.

If you have irregular periods, it can be extra difficult to calculate when you will ovulate. In such instances, ovulation tests are a good tool.



When is the greatest chance of the egg being fertilized?

It is best to have intercourse or introduce sperm from about 3 days before and on the day of ovulation itself, because the egg can be fertilized for a maximum of 24 hours. Then there is the greatest chance that the egg will be fertilized.

When the egg is released, it is caught by the fallopian tube and travels down to the uterus. During this migration, it can be fertilized by the sperm. The egg is fertilizable for one and a half to one day. If the egg is not fertilized, it lives for about a day.

But the sperm can live inside the uterus for several days! They can wait in there for the egg to arrive. Therefore, it is better to have intercourse 2-3 days a week, regardless of which day of the menstrual cycle it is, than to try to pinpoint the exact day of ovulation.


What happens if the egg isnt fertilized?

Once the egg has been released from the ovary, the ovarian cyst transforms into the corpus luteum, which produces hormones that are important for building up the lining of the uterus.

If no egg has been fertilized and stuck in the mucous membrane, the corpus luteum is no longer needed. Then it shrinks and the amount of corpus luteum hormone drops. This is the signal that causes the mucous membrane to be ejected as a hemorrhage and you get a period.

Facts on ovulation

After a period, the production of the hormone FSH (follicle stimulating hormone) increases in the pituitary gland. The hormone affects the ovaries and causes the egg to mature inside its cyst in the ovary.

During the time that the egg matures, the ovaries in turn increase the production of the female hormone estrogen. This hormone also causes the mucus in the cervix to change. The mucus becomes easily permeable so that sperm can get through and also makes it easier for them to survive. The high estrogen levels also affect the pituitary gland, which signals the ovaries via the hormone LH (luteinizing hormone) that ovulation should occur.

When the follicle (follicle) ruptures, the egg is released. The follicle transforms into a small organ, the corpus luteum, in the ovary. The corpus luteum produces hormones. The most important hormone is corpus luteum hormone (progesterone), which causes the lining of the uterus to grow and prepare to receive the fertilized egg.

Source: and fact-checked by RFSU clinic

Last updated: 2023.06.07