I was terrified just reading this. Choking is one of my worst fears, especially in regard to my children.
Like the others said, make sure to learn how to do the self heimlich, with a chair or your own fist...and do it as quickly as possible! Apparently, you only have, I think, 60 seconds or less before you pass out from lack of oxygen. :shock:
Big brave hugs to your son and you!