In the menstrual period is not easy to get pregnant, mainly because: 1, the menstrual period is in the follicular phase, the follicle has not matured, this time there is no ovulation, the same time will not be pregnant. 2, in the menstrual period, a large number of semen will be with the menstrual blood outside the vagina, even if there is an ovulation, the chances of getting pregnant is also very low, so in the menstrual period of the same time will not be pregnant. The menstruation period is a normal physiological period for women, but in the menstruation period can not cohabit, mainly because: 1, will cause infection. 2, may lead to endometriosis, will cause serious consequences, so the menstruation period can not cohabit.