menstrustion

Yes. Very possible. And according to webmd.com "Washing or urinating after sex will not stop the sperm that have already entered the uterus through the cervix." And... "Pulling out before the man ejaculates, known as the withdrawal method, is not a foolproof method for contraception. Some ejaculate (fluid that contains sperm) may be released before the man actually begins to climax. In addition, some men may not have the willpower or be able to withdraw in time. Kaya lagi sinasabi ng mga OBs na withdrawal is not a very effective birth control method.