Progesterone help get pregnant?

Been ttc for 2 yrs now and i had a mc about a year ago where i clearly felt my progesterone levels drop 2 days before i actually lost it. Afterwards i asked my doctor to check my levels and asked if i could be put on a progesterone supplement and he refused both. He says there is no proof that it helps anything and that as long as im getting a positive ovulation test i should be fine! He also said there is no point in testing them until i become pregnant again. Idk what to do. It seems everyone is taking progesterone but my dr wont even consider it! What do i do? He did schedule me for a hsg test though, which i figured would be more of a last resort?