Progesterone Question

I am currently 4wks 2days and have had three early losses prior to this. My former OBGYN never checked progesterone. I switched to a new place and they are having me get a blood draw to check progesterone. If it comes back that my levels are low, is it too late to try and get them back up in order to have a successful pregnancy? Obviously I will talk to my doctor tomorrow when they call with results but was curious to see if anyone else had experiences to share.