hii, hcg takes an average of 2 weeks to leave the body. 4 weeks being the max...
i had a termination 10 weeks ago today though and i STILL have a small amount of hcg in my system and were still unsure why.
try asking your doctor again to take a blood sample and see. if tests are coming up negative though you should be ok :) x
Lots of peoples levels go back down to 0 within the same week and some it can take a couple weeks. If you are showing negative on a pregnancy test than that is a good sign your levels are almost at 0 if they aren't already. When I had a miscarriage I ended up getting pregnant again within 6 weeks so I'll keep my fingers crossed for you! I wish you lots and LOTS of sticky baby dust!