When is a Woman Most and Least Fertile?

What do we mean when we talk about the most fertile period? Which days are favorable for conception? And which are not? This article will help you to answer “When is a woman most fertile?”.

There are days throughout the whole menstrual period when you have the highest chances to get pregnant. When eggs are ready for fertilization and only wait for the moment when they can begin to divide, the conception of a new life occurs.

This readiness lasts for three days. Normal male sperm, despite their apparent randomness, also live for 2-3 days. It turns out that you are most fertile in the middle of ovulation.

The best days to conceive a baby are not the peak of ovulation but the days before it. Then sperm will have enough time to stay in the fallopian tubes, where they wait for the moment of the release of an egg. So when is a woman most fertile, how to determine?

There are several ways to determine when you are most fertile.

  • Calendar method
  • The nature of discharge
  • Basal body temperature method

Calendar Method

The method is based on the following principles:

The cycle begins on the first day of your menstruation, the cycle can last for approximately 26-32 days. If you want to create a calendar of your cycle in order to determine the most fertile days, it is necessary to have a regular menstrual cycle.


If you have a 28 days cycle, fertile days fall on the 11-16 days. The 14-15 days are the most suitable days for conception.

It is also necessary to bear in mind:

  • Ovulation occurs 14-16 days before your next menstruation (if there are no gynecological diseases, stressful or other adverse effects)
  • An egg after ovulation lives for 24-48 hours
  • Sperm in a woman’s body lives for 3-5 days

Fertilization can occur when sperm gets in the vagina 3 days before ovulation and 2 days after it. An egg can be fertilized no earlier than 24 hours after leaving the ovary, and sperm can remain in the vagina for about 3-5 days. Consequently, the probability of conception is the highest when there are 3-4 days before ovulation and for the next 4 days.

However, this method has its difficulties. Firstly, menstrual periods do not always start at the same time and do not always last for the same number of days. And secondly, ovulation can take place, not in the middle of the menstrual cycle but some days later or earlier. Moreover, ovulation may not occur if there are any adverse external conditions or serious illnesses. Therefore, not always this method helps many couples to conceive.

The Nature of Discharge

You should start to pay attention to the constituency of your cervical mucus (discharge from genital organs) since the last day of your menstruation. There is not much mucus immediately after menstruation because the vagina becomes a bit dry during this period.

During these days conception is impossible. A few days later discharge is changed: it becomes more viscous, like glue. Over time, the mucus becomes thinner and facilitates the promotion of sperm. There is a feeling of wetness in the vagina.

During the period of ovulation, cervical mucus is more watery, transparent. This type of mucus is most favorable for the activity of sperm and its movement, and consequently for conception.

After ovulation, the amount of mucus is reduced.

Basal Body Temperature Method

Basal body temperature should be measured in the mouth (orally) or in the rectum every day, after waking up, but not getting up.


The temperature should be measured at the same time, after 6 hours of sleep.

In order to measure the temperature, it is better to take a mercury thermometer. Some infectious diseases in women, accompanied by an increased body temperature, inflammatory diseases of the genitourinary system, a decreased duration of night sleep, stress can affect the measurement results. If you have any of causes mentioned above, you need to mark them on the chart.

The measurement results are entered into a special table. The temperature slightly decreases about one day before ovulation, it increases by 0.3 – 0.6 degrees during ovulation and remains the same until the end of the cycle, we can draw a graph and determine the day of ovulation according to these data.

In addition, a complete picture of the body temperature changes recorded in the form of a graph also helps to determine the absence of ovulation and the cause of infertility.

Moreover, this method will be helpful if you have an irregular menstrual cycle when it is impossible to calculate the best days for conception.

However, this method is not suitable for women who use hormonal drugs, which distorts the results of the measurement.

There is also a special test for this purpose; it is almost the same as a pregnancy test. These tests allow us to determine the level of hormones in urine, which is released in large quantities for 24-48 hours before ovulation.