The vast majority of patients with regular menstrual cycles are relatively in the safe period 2 days after the end of the menstrual cycle, but there are also special circumstances that lead to the existence of ovulation, so 2 days after the end of the menstrual cycle is not an absolute safe period.
Usually the average female menstrual period is 3-7 days, so 2 days after the end of menstruation, that is, the 4th-9th day of the menstrual cycle, is not consistent with ovulation, generally in the safe period; two days after the end of menstruation coitus, belong to the relative safe period, because this period of time the uterine lining has not been thickened, follicular development has not matured, so the general situation is safe to coitus.
A small number of women may also have a special situation of extra ovulation, so 2 days after the end of menstruation has a chance of pregnancy.
Therefore, 2 days after the end of menstruation is relatively safe for the vast majority of women with regular menstrual cycles.