progesterone down😥

Hey all! I'm about 5 weeks pregnant. I had bloodwork on Thursday and Saturday and my HCG was good (went up from 1098 to 2285), but my Progesterone went down from 26.2 to 21.2... Should I be worried? I am going in this Friday and my doctor said all looked good, but I'm nervous. This is my first pregnancy and I've never experienced any of this, but I've heard progesterone dropping is a sign of miscarriage. Any advice would be appreciated!!