Ovulation normal menstruation normal can not get pregnant may be due to male problems, coitus time, uterine tubal abnormalities, immune factors and so on. 1. male problems: male semen has abnormalities, such as sperm count is low, the vitality is relatively poor, or the sperm quality is not good, resulting in difficult to get pregnant. 2. Intercourse time: both men and women have less frequent intercourse, or the time of intercourse does not meet the time of ovulation, resulting in no pregnancy. 3. Abnormalities of the uterine tubes: the combination of sperm and egg needs a channel, if the fallopian tube is obstructed, the sperm and egg can not be combined to form a fertilized egg. Fertilized eggs need a suitable place to lay, if the uterus has abnormalities, such as endometrial polyps, uterine adhesions, etc., can also lead to infertility. 4. Immune factors: Both men and women produce antibodies due to immunity factors, such as antiphospholipid antibodies and antisperm antibodies, so that the sperm and egg can not be combined, or the fertilized egg can not develop normally, leading to infertility. If both men and women have normal sexual life without contraception for at least 12 months without pregnancy, it is called infertility, and you need to go to the regular hospital in time.