What Causes Brown Stringy Vaginal Discharge Postpartum?

I m 8 weeks postpartum and I stopped bleeding about 4 weeks postpartum. I started my period at 6 weeks postpartum, it lasted a little longer than usual which I heard is normal especially since I started both control at the same time. I had a pap smear and exam 4 days ago and since then I have been having brown stringy discharge. Is this normal?