Reasons for not getting pregnant during ovulation:

1. Fertility disorders: Some fertility disorders, such as fallopian tube blockage, uterine problems, ovarian problems, etc., may make it difficult to get pregnant.

2. Poor sperm quality: Sperm quality is one of the key factors affecting pregnancy. If the sperm quantity, motility and morphological quality are poor, the chances of pregnancy are reduced.

3. Female factors: Female factors are also one of the factors that affect pregnancy. For example, women's irregular menstrual cycles, taking medications, smoking, drinking, etc. may affect pregnancy.

4. Environmental factors: Environmental factors are also one of the factors that affect pregnancy. For example, pollution, noise, radiation, etc. may affect women's fertility.

5. Psychological factors: Psychological factors are also one of the factors that affect pregnancy. For example, anxiety, stress, etc. may affect a woman's fertility.

6. Other factors: There are other factors that may make it difficult to conceive, such as male fertility problems, female age, etc.

If you want to have a successful pregnancy, you need to consider and adjust from many aspects. It is recommended that both couples undergo a health check-up and consult a professional doctor to understand their own situation and develop a pregnancy plan that suits them.