Progestorone question?

Molly
So I went for blood work last Monday at 4w 1d and my hcg was 118 and progestorone was 18. Went again Wednesday and hcg was 323 and progestorone was 15.9. Nurse wasn't concerned that progestorone went down but I'm still a little worried. I know it's not too low at this point but did anyone else have it go down and have a positive outcome?