I was off and on birth control for almost 4 months then around the time I was suppose too get my period I was having very bad cramps too the point where I could hardly even walk. I sat down in the restroom hoping that the clot would pass but it didnt but when I got up and walked some more I felt a hugh plop!! then the pain went away shortly after.When I went too the restroom I saw a big grey clot the size of my hand that and it was folded over almost like pocket on the front of a shirt and it also had red vein like stuff on it. Could this have been a miscarriage? I didnt think I was pregnant because I had been on and off the pill.