Miscarriage and Progesterone pills

Hello, I am new to the group. To give a little background— my husband and I have two children. Two boys who were conceived quickly and were normal pregnancies. In the last 12 months I have had three early miscarriages. I recently have sought a fertility specialist and have had blood work, biopsy on my endometrium, and ultrasound done. Long story short, everything looked healthy. My great concern is that he does not think progesterone is something worth looking into. He claims ( which I believe he might be right 🤷🏼‍♀️ he knows more than me...), that progesterone doesn’t do anything for a women having recurrent miscarriages. Has anyone seen a doctor who has stated otherwise? Or know if any true evidence that lack of progesterone can be a leading cause for recurrent miscarriages? He believes mine is fine. Either way, I am taking 200mg prescription progesterone because I told him at this point if I was to miscarry again I would blame the lack of progesterone and the doc agreed I would prob blame him so he said- “Yes, take them. However, they medically do not do anything for you.”

Thank you in advance to anyone who knows anything about this or has experienced something similar. God bless you.