A couple of months ago I had a colposcopy for bleeding after sex, everything was fine and the biopsy apparently came back clear. I have been in a lot of pain with my lower back along with pelvic pain. Today I had extreme pain like a period but 10x worse, when I went to the toilet to check I was having a blood clot, which was quite big. A few months ago as well I woke up and I had bled through my underwear, pyjama bottoms and the bedding.

What could it be?