Period refers to menstruation. There is no medical concept of safe period. Safe period is relative to ovulation, other than ovulation other time period. Ovulation refers to the day of ovulation and the time period of four days after five days before and after the day of ovulation, the day of ovulation is usually 14 days before the next menstrual period, generally about a week before the onset of menstruation for the safe period. The safe period is not absolutely safe, it is recommended to take contraceptive measures.
Safe period usually refers to the removal of the menstrual period, the day of ovulation and ovulation day five days before and four days after the time period, during which the chances of pregnancy will be relatively small, but there is still a chance of accidental pregnancy. Therefore, the safe period is only a relative term, during this period of unprotected intercourse is still possible to get pregnant.
It is worth noting that, regardless of whether it is a safe period or not, in the absence of the need to prepare for pregnancy, should take contraception, for the menstrual cycle of unstable people, the safe period may vary, it is recommended to judge according to their own actual situation.