Irregular periods 16 months pp

I’ve had two periods last month which I thought because I got back on birth control. I’ve been absolutely bloated to the point my stomach is hard. Acne like crazy. Took tests came back negative. Period stopped on the 1st of February and I started bleeding again yesterday. They’re heavy and very dark. No pain with them. I’m calling my gyno up tomorrow but what do you guys think it could be? I’m also breastfeeding still and I take the birth control pill. I also was taking hair, skin and nail vitamins because I was balding from pp and I stopped the vitamins yesterday to see if that was causing something..