The so-called safe period usually refers to the 7 days before and 8 days after the menstrual period, for example, if the menstrual period comes on the 10th, the safe period is between the 3rd and the 18th. Ovulation is mainly for women with a regular menstrual cycle, and usually refers to the period 3 days before and 4 days after the day of ovulation. Since there is ovulation during ovulation, the chances of pregnancy are particularly high if you have intercourse without using contraception. However, the safe period is not 100% safe and can lead to unplanned pregnancy due to abnormal ovulation.