Pregnancy may occur if you have intercourse one week after your period, so couples who do not want to have children should use contraception. If a woman’s menstrual cycle is relatively regular, one week after her menstrual cycle, she will usually enter the ovulation phase and discharge a normal egg, which will lead to a successful pregnancy after sexual intercourse. Even if a woman does not ovulate one week after her menstrual cycle, some women may experience abnormal ovulation and may expel an egg, which can lead to pregnancy after intercourse, although the probability of this is low. Therefore, couples who do not want to have children must take effective contraceptive measures during sex, such as condoms, and women who want long-term contraception can place an intrauterine device to prevent unwanted pregnancies.