Milk coming out of baby boy's nose

J • Mother of 5, Married to my best friend 7/30/15. Ready for everything God has in store for us! 😍😘
Hi Mommies, 
Has anyone experienced this or know what could be causing it.... 
When I am laying on the side and feeding my 3 week old, the milk sometimes leaks out his nose. 
I spoke to my Dr about it and he said I could possibly be over feeding him but I know I am not. It can be hours later after he wakes up and it still would do it. 
He doesn't seemed bothered by it but it bothers me to see milk leaking from his nose. Help!