The first seven days after eight is a calculation method used by most people for contraception, referring to the seven days before menstruation and the eight days after menstruation, during which intercourse is less likely to result in pregnancy. This period of time is less likely to result in conception than other periods of time, but it is not absolutely risk-free, and the risk of using this safe period of contraception is still relatively high when compared to other means of contraception such as the pill and contraceptive devices. In addition, there are many ways to determine the date of ovulation, women can also be ovulation test paper, measuring the basal body temperature and observe the cervical mucus secretion to calculate the ovulation period. If the woman in the ovulation period after intercourse, menopause, pregnancy reaction, etc., consider the possibility of pregnancy, it is recommended to timely medical care, under the guidance of the doctor, improve the relevant examination, clear cause, and symptomatic treatment.