Having sex during ovulation is one of the most common methods used by couples who want to conceive. However, sometimes even if you have intercourse during ovulation, you may not get pregnant. This is because during the ovulation period, a woman's egg is released from the ovary and can wait for fertilization in the fallopian tube. However, sometimes the egg expires or is blocked by other factors, resulting in infertility.

1. Sperm quantity and quality: Sperm quantity and quality are one of the important factors affecting pregnancy. Generally speaking, during a woman’s menstrual cycle, the number of eggs released each time is limited, while the number of sperm can increase indefinitely. Therefore, even if the sperm survives for a long time in a woman's body, it may not be able to fertilize all the sperm.

2. Formation of the fertilized egg: The fertilized egg is formed after the union of the sperm and the egg. If there is a problem in the formation process of the fertilized egg, such as too many sperm being combined or there is a problem with the fertilized egg itself, it may lead to infertilization.

3. Other factors: Other factors, such as women’s health, men’s health, environment and other factors, may also have an impact on pregnancy.

So, how to ensure that sexual intercourse during the ovulation period can lead to successful pregnancy?

1. Accurately calculate dates: Accurately calculating a woman’s menstrual cycle and ovulation is the key to pregnancy. Generally speaking, a woman’s menstrual cycle lasts 28 days, so ovulation begins on the 14th day of the menstrual cycle and ends on the 23rd day.

2. Choose the best time: Having intercourse during a woman’s ovulation period is the best time to get pregnant. However, sometimes a woman's menstrual cycle is unstable, so even if you choose the best time, you may not be able to get pregnant successfully.

3. Avoid excessive sperm: Sperm that survive for a long time in a woman’s body may have an impact on pregnancy. Therefore, in order to avoid excessive sperm, other measures can be taken, such as preventing them from surviving too long in a woman's body.

4. Healthy lifestyle: A healthy lifestyle can improve women’s fertility, including maintaining a healthy diet, regular exercise, and adequate sleep.

In summary, even if you have intercourse during ovulation, you are not guaranteed to get pregnant. Therefore, couples who want to get pregnant should take correct measures to ensure the quantity and quality of sperm and choose the best time to have sexual intercourse.