Hi everyone, I got my last period on 12/11 and it ended on 11/18. Eight days later ( 12/26) my boyfriend and I were having sex and I started bleeding... A lot. It wasn't like menstrual blood though, it was bright red and clear, also kind of stretchy. It went away a few hours later and that night I got a sudden very sharp pain in my lower back, and now for the past three days I've been lightly spotting, and also accompanied by  a weird cramping feeling in my lower left abdomen. What could be causing this... I sort of ruled out pregnancy because I did just have my period and my boyfriend and I use condoms 98% of the time. I also was thinking its a cyst because I've had one in the past but it drained and went away on its own and I'm not sure if sex could cause a cyst to rupture and bleed. Please any opinions or help is appreciated!