Unser Blog

Ovulation calculator: How can I calculate my fertile days?

20 Jan, 2023

Ovulation calculator: How can I calculate my fertile days?

If you want to have children, it is of course an advantage to know when you are ovulating. This is because successful fertilisation of your egg is only possible for a few days each month. If you have tried in vain to get pregnant, you should keep a cycle calendar and calculate your fertile days. In the following we will explain what you need to pay attention to.

Calculating fertile days - the most important things at a glance

  • An ovulation calculator can help you calculate your fertile days.
  • Monitoring your cycle can also provide your gynaecologist with important information if needed.
  • Ovulation only lasts a few seconds and the egg is fertile for 12 to 24 hours.
  • If you are not able to get pregnant, it may be due to your lifestyle, your age or your husband.
  • Calculating your ovulation is not a substitute for contraception.

Why you need to keep track of your menstrual cycle

The length of your menstrual cycle can vary from woman to woman. If you know how long your cycle is, you will know when you can expect your next period. It also gives you the opportunity to find out when your fertile days are. 

period panties

You can use this information either to increase your chances of getting pregnant or to support the contraceptives you use. Please note, however, that you cannot use an ovulation calendar alone as a reliable contraceptive.

In addition, your records can also be helpful if you suffer from menstrual pain or other abnormalities and complaints in connection with your menstruation and cycle and therefore need to see a gynaecologist.

What is ovulation?

Ovulation is one of the four phases of the female cycle. It follows the so-called follicular phase, during which the eggs mature in the ovaries. As protection, the eggs are surrounded by the follicle. This is a shell that is filled with fluid. When you ovulate, this membrane bursts and releases the egg so that it can travel down one of the fallopian tubes to the uterus. This process, which only takes a few seconds, is ovulation.

When does ovulation occur?

Ovulation is triggered by changes in your hormone balance.

When exactly you ovulate depends on the length of your cycle. Apart from that, health factors can also play a role in this connection.

Basically, you can assume that you ovulate about two weeks before each menstruation. Depending on the length of your cycle, it may take a little more or less time after ovulation for your period to start. So if you want to calculate your fertile days, you need to know as precisely as possible when you will have your next period.

How long is fertilisation of the egg possible?

After ovulation, your egg is fertile for just 12 to 24 hours. If it is not fertilised during this time, you will not get pregnant. In this case, your next period will start after about 14 days and your cycle will begin again.

How does ovulation announce itself? 

There are several signs that you are ovulating. With a little practice, these can help you determine your fertile days.

Period Underwear

The following symptoms are associated with ovulation:

  • The level of luteinising hormone, which triggers ovulation, increases.
  • The body temperature immediately after waking, known as basal body temperature, is slightly elevated.
  • The cervix softens, opens and sits much higher in your vagina.
  • The vaginal discharge increases and also changes both its colour and consistency.

In practice, it is not easy to recognise these signs of impending ovulation. For example, you need to take your basal body temperature regularly under the same conditions to notice any changes.

Palpating the cervix correctly requires some practice, and to determine your LH level you need an ovulation test, which of course you also need to use correctly.

How can I calculate my ovulation?

If you want to calculate your ovulation, you have several options for doing so, some of which differ significantly in terms of the effort involved and the accuracy of the calculation.

First, of course, you could simply estimate when you will ovulate next. However, since not every woman's cycle is the same length, this only makes limited sense if you want a meaningful result. Using an ovulation calendar or cycle calendar is much more accurate.

For this method of calculating fertile days, you need to know how long your cycle lasts on average and when your last menstruation began. With this information, you can then use one of the free ovulation calculators available on the internet.

menstruation underwearApart from just estimating and calculating with an ovulation calculator, you also have the option of taking a number of measurements if you want to know when you are ovulating. As mentioned earlier, you can measure your LH level with an ovulation test or keep a record of your basal body temperature so you can see the temperature rise just before you ovulate.

Why can't I get pregnant? 

If you have been using an ovulation calculator for a while and still haven't become pregnant, there can be many reasons for this.

Possible reasons for the lack of success are, for example:

  • Being underweight or overweight
  • The use of drugs
  • Excessive alcohol consumption
  • Severe stress
  • An unhealthy diet
  • Advancing age

Apart from this, it is of course also possible that the reason for the lack of pregnancy is not to be found with you, but with your partner. It may therefore make sense to have your husband checked to see if he is fertile.

Can you use an ovulation calculator for contraception?

Not every woman who wants to calculate her fertile days does so because she wants to get pregnant. For some women, the opposite is true. If this applies to you, please be aware that an ovulation calculator is not a reliable method of contraception.

The length of your cycle and the exact time of ovulation can vary for a number of reasons, which you may not always notice in time. In addition, male sperm can survive for several days. Therefore, it is not absolutely necessary for you to have unprotected sexual intercourse immediately after ovulation in order for fertilisation to take place.

If you want to be on the safe side, you should not only calculate your fertile days, but also use a contraceptive such as condoms or the pill.