I'm 18, and about 2 weeks after having unprotected sex, I was due for my period on 9/23. It didn't come. (Usually my period comes within 1 or 2 days before the day it came the previous month, so i knew something was wrong.) But 3 days later, 9/26, I started having this brown discharge. First it was dark, then it got lighter, but only lasted for about 4 days. I don't think it was my period, because there was never any blood in it. Just brown stuff. So I thought I could be pregnant. Now this month, 10/10, I woke up to what looked like my period, except it was 13 days before my regular cycle would start. I had bad cramping & it was a really heavy flow with lots of clotting. But it only lasted like 2 days, because today I have barely had anything except for a little bit of brown and cramping. I'm wondering if I really was pregnant, and could have had a miscarriage, or if my cycle is just messed up. Help would be appreciated... I'm really confused.