Within a week of menstruation is a physiological safe period, in this period of intercourse the chance of pregnancy is relatively low. Most women use the safe period for contraception, but the safe period is not absolutely safe, some women may also have extra ovulation, if there is extra in this period, ovulation coitus is also pregnant. So whether it is within a week of clean menstruation or within a week of the onset of menstruation, although it belongs to the physiological safe period, but there is also the possibility of pregnancy. If a woman does not plan to have children, she should try to take effective contraceptive measures, such as intrauterine devices or oral short-acting contraceptive pills.