Abdominal Pain/Long Period

My normal menstruation is every 3 weeks, lasts 7 days, no more no less. The insane menstrual cramping starts 2 days before I start bleeding and normally stops on day 2 of bleeding. I was diagnosed with a bicornate uterus last year if that means anything.

Well I started my period on Thurs, 7/22 (10 days ago) and I'm bleeding heavy. I have small chunks sometimes which is normal for me. I have had keel-over pain since Tuesday 7/20 and they have not stopped. I can't much say if the pain is more or less than normal because severe pain is "normal" for me. I have gone through one box of tampons already and I'm on my second box. For the past year as it were, I have been more prone to fainting spells too. My last fainting spell happened at my friends house on my last period about 3 weeks ago.

As far as sex life, my bf and I are rediculously active but we do use contraception. We always check condoms for holes/rips before we throw them away and we haven't come across a torn one yet. So, we're pretty confident I'm not pregnant. I haven't taken a test yet, honestly, I'm kind of scared. So I guess I have a couple questions:

Can an active sex life affect menstruation at all?
If this is a miscarriage, would a pregnancy test pick it up as positive for pregnant?
If yes, then would a pregnancy test prove that I could be miscarrying?
What are symptoms of miscarrying?

Last but not least, I'm a clean freak when it comes to my privates. I wash my hands and nails before doing so, but I clean myself twice daily because I have a phobia for infections. Anyway, when I was cleaning myself tonight, I pushed my fingers in as far as I could and I can feel a hard almost-golf-ball-sized lump (I guess this has to do with fertility depending on if its hard or soft?) Plus I tried to find diagrams online to find out what that lump is (I know all females have it) and I can't find any diagrams that shows a lump. Anyway when I was cleaning, I noticed what seem to feel like a hole. Since I clean myself constantly, I have never noticed this "hole" before but could it be significant as to why I'm bleeding so much and for so long?