How to Calculate a Woman’s Fertile Days?

Fertile days are the days in a woman’s menstrual cycle when she is most likely to become pregnant. During these days, the egg is released from the ovary and travels through the fallopian tubes to the uterus, where it can be fertilized by a sperm cell.

During this period, having unprotected sexual intercourse carries a higher chance of pregnancy.

Calculating your fertile and infertile days is very important when trying to conceive. Many women don’t know their cycle, which prevents them from knowing when they are most likely to become pregnant.

How to Calculate the Fertile Period

There are different methods to calculate a woman’s fertile days. One way is to keep a record of the length of your menstrual cycles. If your cycles are regular, ovulation usually occurs 14 days before the start of the next period. For example, if your cycle lasts 28 days, ovulation will occur around day 14.

Another way to identify your fertile days is by measuring your basal body temperature (BBT). BBT rises slightly during the luteal phase, which is the phase after ovulation. You can take your BBT every morning before getting out of bed. If you notice an increase in your BBT, it’s a sign that you’ve ovulated.

You can also use ovulation tests to detect the rise in luteinizing hormone (LH) that occurs just before ovulation. Ovulation tests can be purchased at pharmacies or health product stores.

How to Calculate the Fertile Days of Your Menstrual Cycle

To determine the fertile days within a menstrual cycle, it’s important to keep in mind that the probability of conception varies throughout the cycle.

While ovulation is the time of highest fertility, sperm can survive in the female reproductive tract for several days. Therefore, it’s possible to become pregnant even before ovulation or up to several days afterward.

Pregnancy is even possible during menstruation, although the probability is very low.

The key is to know when ovulation occurs and plan to have sexual intercourse around that time. Using our ovulation calculator will help you.

Knowing the phases of each woman’s menstrual cycle makes it possible to calculate fertile days. The lifespan of an egg is about 48 hours, and sperm can survive in the female body for up to 72 hours after ejaculation. Therefore, to the most fertile day you should add 3 days before and 2 days after.

How to Calculate If Your Cycle Is Irregular

• Write down the length of your cycle. For example, note how often you’ve had your period over the last six months and the date of your last period. With this data, the calculator estimates your average cycle length and subtracts 14 days from your last period.
• For instance, if you have an irregular cycle and your period comes every 34 days, you would still subtract 14 days, so ovulation would occur around day 20 of your cycle.
• If your cycles are too irregular, this method won’t help you calculate your fertile days. In that case, we recommend seeing a specialist.

Symptoms to Identify the Fertile Period

• Changes in body temperature: Use a thermometer to check if your body temperature has risen slightly.
• Abdominal pain: In some cases, you may feel sharp pain in the abdominal area caused by the rupture of the follicle that releases the egg. This releases fluid that irritates the peritoneum and causes pain.
• Breast sensitivity: Many women experience increased breast tenderness during ovulation.
• Changes in vaginal discharge: Thicker or differently colored discharge is a sign of ovulation.
• Increased libido: You’re more fertile during ovulation.
• Mood changes: Hormonal changes can cause mood swings during ovulation.
• Acne and pimples: During ovulation, estrogen and progesterone levels rise. These hormonal changes can increase sebum production, which may lead to acne and pimples.

Tips for Having Effective Sexual Intercourse During Your Fertile Days

With this information, you should know that the best days for intercourse are days 12, 14 and 16 of your cycle.

It’s important to allow a short rest between each sexual encounter.

Because sperm volume and quality take time to recover, long periods of abstinence (more than a week) can reduce sperm quality by increasing the number of abnormal sperm in the ejaculate.

On the other hand, having sexual intercourse too frequently can lead to the presence of immature sperm.

Finally, remember not to become obsessed with your fertile days. Many factors influence fertility, including stress. Our experts recommend not obsessing over ovulation calculations and instead having sexual intercourse when you and your partner feel like it.

If after a year of trying you still haven’t conceived, it’s advisable to consult a specialist to identify the reasons preventing conception.

Do you have any questions or need more information?

At Fertility Madrid, we specialise in treatments such as egg donation, in vitro fertilisation and artificial insemination, among others.

Please do not hesitate to contact our professionals at our fertility clinic and they will answer all your questions without obligation.

Aida Redondo

Ginecóloga