If you have intercourse after your period and perform internal ejaculation, you will not normally get pregnant because the endometrium has just finished shedding at this time and the endometrium is relatively thin and not conducive to sperm and egg implantation. Also, your period has just ended and you are not ovulating, so the chances of causing conception may be lower. If you have an internal ejaculation after the end of your period, there may be a 10%-20% chance of pregnancy. If you are particularly unsure, you can take the emergency contraceptive pill to prevent pregnancy, as long as you take it within 72 hours after intercourse. The emergency contraceptive pill is not 100% contraceptive and has a 20% chance of failure. You can go to a pharmacy and buy an early pregnancy test about 12 days after intercourse to rule out the possibility of conception.