Ovulation coitus refers to intercourse during ovulation or on the day of ovulation. Usually, there can be no obvious symptoms on the thirteenth day, but a small number of women will experience symptoms such as lower abdominal cramps, small amount of bleeding from the vagina, and breast swelling and pain. If a woman has intercourse during ovulation or on the day of ovulation, she usually has a higher chance of getting pregnant. If the fertilized egg successfully combines and enters the uterus for implantation and development, some women may have no obvious symptoms, but a small number of women may experience lower abdominal pain, small amount of vaginal bleeding, breast tenderness, etc. This is mainly related to the implantation of the fertilized egg and the elevated hormone levels, so there is no need to worry about it. If you are not pregnant after intercourse on the day of ovulation or the day of ovulation, your body may be asymptomatic on the thirteenth day, or you may have breast tenderness. For nausea and vomiting, dizziness and fatigue, gastrointestinal flatulence, breast tenderness and other early pregnancy reactions caused by elevated levels of hormones in the body after pregnancy, most of them begin to appear around six weeks of pregnancy, and gradually subside until they disappear after three months of pregnancy. It is recommended to consult a doctor after the thirteenth day of intercourse during ovulation or on the day of ovulation in order to clarify whether you are pregnant or not. For those who do not need to have children, they should use contraception when having intercourse.