Exactly three weeks ago I started bleeding, a week after I started BC. It was heavy for three days then been normal ever since. about a week and a half into the bleeding, it stopped. But next day it went right back to normal, after I thought it was over. Then today, about a week and a half later, It stopped again, for over right hours, nothing. Then it just came back to normal bleeding again??? I am confused, is it because of the pills?