Aunt that is menstruation, the concept of safe period does not exist in medicine.
Generally speaking, only able to calculate the time after menstruation non-ovulatory period, about 3 days, but ovulation can not be completely accurate prediction, so the so-called safe period does not exist in the exact time, there is no such concept.
After the onset of puberty, ovulation will occur, if the egg and sperm combination, the woman will be pregnant, the past that there is a safe period, and no egg discharge, so this time to have sex after the general will not be pregnant, but in fact, can not use the safe period contraceptive method of contraception, will greatly increase the chances of unwanted pregnancy.
If a woman does not plan to get pregnant, it is best to use scientific and effective contraceptive methods to prevent pregnancy, such as wearing a condom. And women need to pay attention to the private hygiene when having intercourse at the end of menstruation to avoid infection.