Post D&C question

I had a MMC (baby stopped growing at 6w4d) and needed a d&c. I had very scant bleeding the first couple of days, but since then I consistently have discharge when wiping. It has been 3 weeks and 5 days since the d&c. The color is brown, sometimes red. I had an appt with my OB yesterday and she said she wasn’t concerned and that it was normal. She also told me we could resume trying again despite the blood when wiping. In reading about other people’s experience, my bleeding seems to be way longer. I’m paranoid now that there’s retained tissue (though my pregnancy test was negative yesterday) and if I were even able to get pregnant again, whatever is going on in my uterus would cause issues for a future pregnancy. Has anybody experienced something like this?