Longer period than normal

I've never had a regular period. Sometimes they would last a couple weeks, sometimes a week. I've skipped months all together before too. I went to the doctor for this when I was younger and they found nothing wrong with me. So, when my last period started, I began my new birth control (tri-sprintec) and thought nothing of it when I kept bleeding a day after. The first week was a normal, light-ish period for me (I've never really had heavy periods except when I first started). However, the second week has been nothing but heavy bleeding (I had to toss a pair of panties last night because it was exceptionally bad). I've been worried this whole week about it because I thought birth control was suppose to help these kinds of things. Isn't it suppose to get it under control? Should I be worried? Today will be my first pill for the third week. This is getting frustrated. I hate bleeding so much. I was thinking about calling my doctor and asking her about it. See if I need to come in for an examination. Ugh, what's wrong with me guys? Any guesses/suggestions to help me out?