Hcg rising but not doubling

I found out last Tuesday that I’m pregnant. Started bleeding that night and bled off and on for 6 days.

My doc had me going in every 48 hrs for blood work and my hcg is rising, but it’s not doubling. The bleeding has completely stopped. I have to wait a week to go back for more testing, and doctor does not seem hopeful.

Wondering if anyone has gone through this and had a successful pregnancy