Bleeding after birth

So I'm breastfeeding and I stop for a few days but pumped the whole time now back to ebf. I thought I was done bleeding then I started spotting and bleeding more now with cramps after I started end again after the few days is that my period or is it bleeding from giving birth still? I'm 4 weeks PP. The bleeding is bright red with small clots the doc said my uterus was still kinda high also I know I'm not suppose to have sex but i did at 3 weeks and I didnt start bleeding like this until last night