Sometimes when you do the deed and your cervix is closed it will come out. Also the sperm may not be coming out. When they ejactulate in us there is more than just sperm. It could be that your body is just expelling the other stuff in the semen and keeping the sperm. I hope this helps and good luck to you:)
Honey, semen does come out, the vagina is a cul de sac, not a freeway. The sperm will swim upstream and find the cervix, which it will swim into. Talk to your doctor about the correct timing of intercourse.