Determine the time of ovulation, the first 7 days of intercourse is generally not pregnant, but not absolutely. Couples after intercourse, sperm survival time is generally 48-72 hours, after 7 days after intercourse sperm are basically dead, so this situation women generally will not be pregnant. However, a woman’s ovulation time is not absolutely fixed, and there is always a risk of unwanted pregnancy. If the couple does not have the intention to have children, must do a good job of contraception, do not trust the prescription, and do not take the chance that will not be pregnant, if accidentally pregnant, the fetus is innocent, every life should be cherished. Couples after coitus if there is an abnormality, it is recommended to consult a doctor in a timely manner, with the help of a doctor to clarify the cause of the disease for targeted treatment.