Period wont stop bleeding continuously

Ok I know I may have started the BC pill on a bad day (1st day of my period) but I didn't even know I would have my period that early. Its 10 days later. I stopped taking the pill just a few days ago. My period is still going on & very heavy that I sometimes have to sit on the toilet for minutes. I'm a little scared & I want to know if this is normal. In between this period, I had days where I just spotted. Since yesterday its been crazy. Please help.