Brown discharge

I’m supposed to be 8 weeks tomorrow. A week ago I thought I miscarried because I lost a lot of blood and even passed a couple clots so my doctor had me go in on Tuesday for an ultrasound

and everything was fine with my baby. I’m not bleeding red anymore but since then I’m having brown discharge. Sometimes it’s light, but if I do anything at all, even light house chores it gets heavier. Has anyone had this? Could it be an infection? My doctor says it’s normal but it still worries me.