Doctor doesn’t want to track my progesterone

Hi this is my first pregnancy currently W5D5 and had an ultra sound today. I have pcos and have been concerned about having my progesterone tracked. Last week I insisted my doctor to check progesterone and it came out to 14 which he said was good. Today at the appointment he basically told me he wasn’t going to check my progesterone levels because supplementation hasn’t been proven to work and it can be invasive and expensive. I left the appointment feeling uncomfortable with him not wanting to track my progesterone. Any suggestions on what I should do? Thanks in advance !