Miscarriage(has anyone been through this) plz help

. I miscarried Feb 17 of this year and bleed for almost 10 weeks. Doctor dis not do a d&c or give any meds. I stopped bleeding for 2 and a half days and now I'm back bleeding lighting but very bad cramping. I've been so worried and feeling that something is wrong. They did two ultrasound and both said I've passed everything but I don't understand why I'm still bleeding