Just depends girl, it took awhile before I tested negative. I can't remember how long.
It took me about a month or so with both of my d&c before my levels were back to 0. It all depends on your body.
Between 8-9 weeks after an 11-week loss and D&C
My first miscarriage at 6 weeks i got a negative test about two days after i stopped bleeding and then found out i was pregnant less than a month later lost it at 8 weeks and got a negative around three days after i stopped bleeding. Depends on your body.