Yesterday while I was having sex, I started to have very bad cramps in my uterus.It felt very tight and 10x worse than any cramps I get with my period. I am not pregnant but recently quit taking birth control pills after 9 years and haven't had my period in the past 9 months which my ObGyn says is normal. I don't know if it was the position(on my knees with man behind-which we use often), but the cramps just kept getting worse. We tried different positions, but the cramping just wouldn't go away. By the time we finished, the pain and tightness in my lower abdomen was so bad I couldn't walk. It felt like I had hurt something internally. The pain was so bad that I started to get very nauseous. I have never had pain like that before and I was very scared. The pain lasted about 30-40 minutes and went away with 800 mg of Ibuprofen. Today I am ok just a little sore but no bleeding or anything unusual. Can you give me any advice?????