What is usually referred to as the danger period is also known clinically as ovulation. Ovulation is 14 days before the next menstrual period, 5 days before and 4 days after. If you have your period on the 16th of the previous month, and you have your period on the 16th of the next month, the ovulation day is around the 2nd, and the ovulation period is from the 27th to the 6th of the next month, which is the ovulation period, also known as the danger period. If your period is irregular, ovulation will also be irregular, which means that the danger period is also irregular. Generally speaking, the two days before and after ovulation are not absolutely safe, that is, this time the calculated ovulation period is from the 27th to the 6th, and the 1-2 days before the 27th and the 1-2 days after the 6th are not absolutely safe. If you don’t have a plan to prepare for pregnancy in the near future, you need to take regular contraceptive measures to avoid accidental conception, because sometimes the danger period can change, and the safe period is relative to the danger period, and if the danger period changes, the safe period is not fixed. Without good contraception, there is a risk of unintended conception.