Miscarriage-then positive test.

I have a blighted ovum on july 3rd and took cytotec to induce the miscarriage. My doctor confirmed it a week later to be a complete miscarriage but he never tested my betas.. only an ultrasound.

About 5 weeks later, I took a pregnancy test and tested positive. I have been testing for 2 weeks and all have been positive but the line fluctuates, it never really gets darker. I went to a new doctor who did lab work and my hcg is at 128 now. I have to rest in a few days but could this be a new baby or residual hormones?