How do i tell my boss that i want to be a stay at home mom?

Be straightforward: Just tell your boss that you want to stay home. In most of this country it's normal and accepted to stay home with your kids while they're small. I don't think anyone will give you a hard time, at least not to your face. When i interviewed for med school i remember one professor saying that if a woman wanted to stay home and raise her kids, she was doing something more worthwhile than medicine.

Be honest: Have an honest conversation with your boss about wanting to be a stay-at-home mom. It is very important especially when the children are very young for you to spend the time with them.