Post Abortion Question

I had a surgical abortion at 8wks and 4 days (April 15th), there was tissue left behind so I wound up having to take the pills to pass the remaining tissue at 2 wks post op. It has now been 7 weeks since the surgical procedure and I still  have a very faint positive test. Is this normal? Everything I try to read has different opinions so it's very confusing. I'm assuming since I still had remaining tissue 2 weeks after then I should begin my weekly counting there which would make it 5 weeks since I took the pills instead of 7 weeks? I don't want to have another baby and now I have anxiety.