The end of menstruation 3-5 days can have sex, when the menstruation is completely clean coitus will not cause gynecological infections, if premature coitus, vagina or uterus with residual blood, coitus will cause re-bleeding is also prone to cause vaginitis, the cervical opening is not completely closed, the inflammation will be infected with pelvic inflammatory disease, and so on. 3-5 days after the menstrual period belongs to the safe period, in this period of coitus will not be pregnant, a week after the menstrual period belongs to the ovulation period, if coitus need to use a condom can prevent pregnancy. Both parties need to pay attention to hygiene, it is best to use warm water to wash the vulva, can prevent gynecological diseases. The body of estrogen secretion is relatively small, the vagina is relatively dry, coitus should be gentle, so as not to exert too much force will cause damage to the vagina.