First period?

I'm 9 weeks PP and on Tuesday I got what seems to be my first period (I don't breastfeed but I am trying to relactate). I noticed how heavy my flow was, it was a brownish color with clots then bright red with more clots, and bigger ones too. The cramping from my belly button down was painful the first two days but it's a little better now. I know pregnancy changes everything but I feel like I should call my DR. Anyone else have a period somewhat like this?