How should I do this ladies

Ok my baby dad and I don't talk anymore he left me out of no where and told me not to call him till the baby gets here. Well we had agreed on him being a Jr. But now I'm having second thoughts I don't want my son having his name and being shit like him. We had already agreed to but I feel like I can change my mind if I want to because I don't like his name anyway. Would I be wrong I don't want him growing up with a name like his dumb ass dad.