HCG after miscarriage

Hi yesterday I went to the hospital since I had really bad cramps and bleeding since the day before. It was confirmed I lost the baby. I was 7 weeks. My level was at 567.8 U/L .

They said it passes naturally so no D&C or pill for me. I have to get blood test in 48 hours and so on until it shows Zero. My fertility clinic said it could take a while..

Anyone had a similar experience and how long did it take to get your level to zero?

Both my arms are already blue from all the blood and vaccine I had yesterday..