使用安全期避孕需事先确定排卵日期。排卵日期可以通过测定基础体温、检查宫颈粘液或通过月经周期规律推算等3种方法来确定。以前一般采用通过月经周期规律来推算排卵时间。多数妇女月经周期为28～30日,下次月经前14日就是预期的排卵时间,排卵 The use of safe contraception need to be determined in advance ovulation date. Ovulation date can be determined by measuring the basal body temperature, check the cervical mucus or by menstrual cycle prediction and other 3 ways to determine. Before the general adoption of menstrual cycle law to calculate ovulation time. Most women’s menstrual cycle is 28 to 30 days, the next 14 days before menstruation is the expected time of ovulation, ovulation