Sperm...idk

Latoya • Ttc...just got off birth control in March. I have a 17 yr old son from a previous relationship. My future husband and I both think now is a good time. Im 32 and we want to try for two babies in 5 yrs.
Sometimes when we have sex the sperm stays in other times it comes out immediately.. When it stays in does that mean my cervix is open?