Me and my boyfriend have been sexually active since I was 16 and he was 18. (I'm now 18 and he's 20). We had sex maybe 3 times in those 2 years, until I got on birth control and now it's 1-2 times a week.  I started birth control when I turned 18 in April. About a month ago, we had protected sex on the last day of my period. I started bleeding during it, and just assumed it was my period since I was still on day #5. My period always lasts 5 days, never a day longer. Once I started bleeding, I didn't stop for another week. (I had my period for 2 weeks straight.) I didn't think anything else about it.