Low testosterone?

Me and my bf have been TTC for almost a year now, but every month I continue to have my period. we both think that he may have low testosterone. He is depressed all the time (sometimes worse than other days), his sex drive is almost completely diminished and it takes him everything he has to get an erection. He's gotten a girl pregnant before and I've been pregnant, so we know we aren't infertile. Does he have to see a specialist for this or can we set up an appointment with a regular physician to see what his testosterone levels are?