Prometrium suppositories?

My doctor just put me on prometrium since I’m trying for another baby and I had 1 shot of depo in February of last year and haven’t been able to get pregnant since having it, my so and I are starting to wonder if it’s himself that can’t have kids or if it’s because of me having the depo. I have 2 daughters from a previous relationship and never had a problem getting pregnant. He also proscribed me folic acid and prenatals, if this doesn’t work should we get so checked out?