Eight days before menstruation is not necessarily a safe period, according to the woman’s usual menstrual cycle to judge. A woman’s usual menstrual cycle is regular, every month is twenty-eight to thirty days to a menstrual cycle, or even longer menstrual cycle, eight days before menstruation may be a safe period, the ovaries did not ovulate the case of coitus, the chances of pregnancy is relatively small. Usually the menstrual cycle is irregular or the menstrual cycle time is shorter, such as in twenty-one days, eight days before menstruation may be ovulation, this time is not safe. Women should be based on their usual menstrual cycle to project the safe period time, the safe period is not absolutely safe, there will be the possibility of accidental pregnancy. Therefore, couples who do not want to get pregnant at the same time, try to do a good job of contraceptive measures. If you have any other questions, it is recommended to consult a professional doctor for guidance.