V.F.
I am from the old fashioned era where babies did sleep on their tummies. But everything I have heard and read say they should be on their back until they can learn to roll over to their stomaches. You can not stay awake all night watching to see if he does not breathe. I think you need to start putting him on his back to go to sleep and let him cry it out. He will eventually learn to go to sleep on his back or learn to roll over to his stomache. Best if he can put self to sleep in any position I think.