Hi, I am 16 and just got placed on birth control a few weeks ago and I started it when my period was suppose to happen but it was already two days late and I have been on the pill for a few weeks now and my period suddenly starts three days ago and it has been very heavy and painful, like I haven t experienced before.I am not even to the last week of the packet yet so I am concerned. What is happening or what should I do? I was told to start them before my period and then my period starts two and a half weeks late and before the last week of the package. I am also having tons of low abdominal pain and the pains are really sharp. A month prior to getting birth control though I had an emergency contraceptive pill and it caused that period to come six days late. Before I ever took that pill and birth control my periods were always spot on. So, I just need to know what s happening or what to do anyway about the birth control.