HCG after miscarriage

Is it normal for the test line to still be darker than the control line 9 days after passing baby and placenta?? I was 9 weeks with a blighted ovum, sac and placenta came out within minutes of each other 3 1/2 hours after I took the pills to induce my miscarriage. I just feel the line should have faded at least a little bit by now. I had a follow up ultrasound Thursday and dr said my uterus looks empty but the lining is still thicker than he’d like so I have to go back sometime this week. Just wondering if this was normal?