How long can a miscarriage last?


So I found out I was pregnant about June 20th and come to find out on July 12 I was going through a miscarriage and a UTI. Honestly I still haven't passed anything and I'm worried It's taking this long I called my doctor twice and she's said she's not concerned. She didn't give me anything for it and I've been taking medication for my UTI but I've been feeling achy and shivering I get hot flashes and I'm nauseous. I get slight fevers like is this normal? I don't even get cramps also I bleed on and off!! I need help or what should I do ??