What are the safety periods? The safety period generally follows the law of "first seven and then eight". Take 28 days as the female physiological cycle, and 7 days before menstruation and 8 days after menstruation as the safe period. "The first seven" refers to the first seven days of menstruation, and "the last eight" refers to the eight days from the first day of menstrual cramps. It should be noted that "the last eight days" does not mean eight days after the end of menstruation.
If a woman's menstrual cycle is less than 26 days, generally speaking, "the first seven" can still be regarded as a safe period, while "the last eight" is not applicable.
3 How to calculate the safe period according to the menstrual cycle, first calculate the date of the next menstruation, and the ovulation period is 14 days before menstruation. The 10 day before and after ovulation is the most vulnerable pregnancy, that is, the dangerous period, during which sexual life should be avoided (if sexual intercourse is to be carried out, other effective contraceptive methods should be adopted). Except 10 and menstrual period, the rest days are safe periods.
It should be noted that the calculation of safe period contraception does not apply to women whose menstrual cycle is less than 2 1 day and more than 35 days, or postpartum or lactating women.
4 Safety period self-test method Through the above safety period calculation method, women can learn to self-test the safety period. For example:
Women's menstrual cycle is 28 days, and the 1 day of this menstrual cramp is 65438+February 2nd, so the next menstrual cramp is 65438+February 30th (65438+February 2nd plus 28 days), and then subtract14th day from 65438+February 30th, so it is 65438. Ovulation days, the first five days and the last four days, that is, 65438+February 1 1-20, are ovulation periods and dangerous periods, and they are most likely to get pregnant. Except the menstrual period and ovulation period, the rest of the time is a safe period.