How to prevent from pregnancy after unprotected intercourse. Actually partner's this month menses starts from 11th to 15July. We did intercourse on 19th July with safe, but not sure about the condom which I used whether it was leaked or not. So I got fear about this. How to find pregnancy, if pregnancy means how to prevent this, is there any possibility to prevent from pregnancy. Do she want to take any medicine, how to check, what are the symptoms for pregnancy. How to find the symptoms. Please help me to prevent from this. Thanks.