Do progesterone levels fluctuate in the first trimester

Kellie • 33 years old, expecting our second in July 2020!!

Hi ladies! I had my progesterone checked again after having it checked 8 days ago and its dropped from 38 to 26. The doctor isn’t concerned at all...has this happened to anyone and everything was fine?? Does progesterone fluctuate a lot during the first trimester?