The chances of getting pregnant by internal ejaculation on the day before menstruation are 1-3%, and the chances of getting pregnant are very low. Because this time is not in the ovulation period, is belongs to the luteal secretion period does not have the advantage of the follicle, so generally will not be pregnant. You can wait patiently for your period after intercourse, as long as your period comes normally, it means you are not pregnant, because your period is the best representative. However, there are some women who have regular periods for a long time, resulting in irregular ovulation cycles. If you have intercourse at this time, there is a 10% chance of pregnancy. If you wait for your period after intercourse, if you haven’t had your period for more than 12 days, there is a chance of pregnancy, so you can buy a pregnancy test to rule out the possibility of pregnancy. If you are unsure about the safe period, you can take emergency contraceptive pills to prevent pregnancy.