Why does my girlfriend always have stomach pain after sex?

Sex should not pain. I believe that it is normal to have pains after sex. Depending on how deep the penetration is, the more sore you may feel. Also depending on the length of time your sex lasts and the number of times you may do it in a day. If you are having really bad pains then it could be some form of allergic reaction to either his semen or the condoms you are using.Please check it out.Good luck.