Miscarriage or Illness

I have unprotected sex usually five times in one day of Saturdays. (That's when I see my boyfriend so we have sex multiple times). I have been spotting for about two weeks now and my spotting has weird little clots and sometimes bigger clots. It has been ranging in consistency as well. Sometimes it is creamy and stringy (like when your wet/ovulating) and sometimes it is sticky. I don't know if I am pregnant and these are miscarriage symptoms, or something else. I have intense abdominal cramps and lower back pain. My periods last for a month or longer and usually spaced out two months in between. (The doctor has checked me and I have a condition where you have excessive bleeding from the uterus which makes my period spaced out) Any ideas I think I may have had a miscarriage, this has been going on for about two weeks.