I wouldn't tell him. You need that child support order to protect both of you. How has been paying? If it isn't by check you could screw him over if you wanted to, so it would be in his best interest to be nice. Many prayers for you.
Thank you ladies. I guess I should have added that he has been paying me for half of the child care expenses. And if I have had to take him to the dr he pays me half of that as well. But to be completely honest, I still get a stomach ache b/c of worry every time that we get into an argument. Although, not b/c I'm worried he's going to physically hurt me or my son, just b/c things got really bad when we first split and I don't want to go through that again... but I have a feeling I might have to.