I need some advice if this is normal or not

I started my period last night and it's a week early. Which is fine, it always comes atleast 5 days early since I've had my son 2 years ago and been on the mini pill. Well since it started last night it came in DARK PURPLE. Which is weird I've never started like that. It is always a light red or pink. I'm a heavy bleeder but NOT THIS HEAVY. Plus it's been 3 weeks since my last period. (I've had problems in the past when I was 16, they would come almost every 2 weeks but my pediatrician didn't give a shit. It eventually stopped.) But since last night the blood has been POURING OUT OF ME. My pad was so damn bad. I've never seen so much blood. Is it normal to bleed like this? Just outta no where? The blood is damn dark. It's never been like that. I cant find anything on Google. Should I call my OB though? I was wanting to get a different birth control anyway since I've stopped breastfeeding a few months ago. I just need some advice if I should worry or not. I'm cramping the same I think. Maybe a little more intense but not as bad...