3 days before menstruation after coitus after menstruation came generally will not be pregnant.
Women who have regular periods usually ovulate 14 days before the next menstrual period, 5 days before and 4 days after the day of ovulation is the period of ovulation, but also easy to pregnancy, in addition to the time of intercourse, the chances of pregnancy are lower, 3 days before menstruation and intercourse and menstruation comes on time generally not pregnant.
In addition, you also need to pay attention to the duration of menstruation and whether there is a change in the amount of menstruation, if it is the same as usual, it means that it is menstruation. If it is different, it may be abnormal uterine bleeding and further tests are needed to rule out pregnancy.
It is recommended that women who do not plan to have children and their partners should take safety measures and go to a regular hospital if their periods are delayed, so that they can receive standardized treatment under the guidance of a doctor.