Hi Tiffany,
Developmentally, you are pushing the earliest age for crawling, and if he's not rolling himself over yet, you are *really* pushing it.
There are steps healthy babies pass through to get to the next step. Sounds like right now, he'd benefit the most from practicing rolling over.
Start with a minute or so of "practice," slow and gentle, 2 or 3 times per day, a minute or so at a time (don't go until he cries, that's too long). *AFTER* he can roll himself belly-to-back *and* back-to-belly without help from anyone, you can worry about crawling.
I know, it's very hard to wait it out for the first one, lol!
Have fun!
t