I'm 23, 5'2", 166 lbs (last week I was only 155 and my eating habits have not changed) so I'm worried about that. I've had problems with my menstrual cycle for the last year. I had been on birth control for several years with no problem and in October 2010 I skipped my period by jumping to the next pill pack. But then ended up in my having my period until some time in April 2011. Doctors sent me for tests, tried new birth control, and nothing worked, it was a never ending menstrual cycle and I lost a lot of blood over the months. But then some time in April 2011 I decided to stop taking birth control and it seemed to have worked a bit. I was period free for 3 weeks. Then menstruated for 1 week. Then period free for 2 weeks... then just finished my 1 week period last Saturday (June 11) but I notice I still have cramps since Saturday. I'm also worried about my recent rapid weight gain. I should mention since I've been off birth control I've had unprotected sex, but the guy pulled out, and I had my period last week so I didn't think pregnancy was possible but now am not sure.