The danger period for women is also called the fertile period or ovulation period. For women with normal menstruation, the ovulation day is usually 14-16 days before the next menstrual period, and the 8 days before and after the ovulation day, together with the ovulation day, is the ovulation period, also called the danger period. For women with irregular menstrual cycles, the irregularity is usually due to an abnormal follicular phase, which can be as long as 20 days or as short as 10 days, so it is more accurate to push forward according to the time of menstruation, which is usually 14 days before the time of menstruation. For women with normal menstruation, intercourse during ovulation has a higher probability of conception. If you do not intend to have children, it is recommended to use condoms for contraception or take emergency contraceptive pills within 72 hours after intercourse, but the success rate of emergency contraceptive pills is lower than that of condoms and it is more harmful to women’s health. For the danger period, another concept is “safe period”, which usually refers to the time other than the danger period, some people think that the chance of conception during this period of intercourse is small, and use it as a means of contraception, but in fact, the way to calculate the safe period of contraception is not strict, and the failure rate is higher than other contraceptive methods, so it is not recommended to use this This method is not recommended.