I have also been having cramps during sex. One time it was so bad that my fiance was like dont touch him any more cause it scared him.
I had cramps after sex when I was pregnant. When you have an orgasm your uterus contracts. Which is part of why they say to have sex to induce labor. But unless there is some sort of medical reason, sex should be completely safe during pregnancy. Also I don't think the semen got stuck in your stomach. lol.
Oh that makes me feel alot better thankyou! I maybe panick far to much lol!!