changing name on birth certificate

i am the unwed mother a 14 mo old. His father and I never married but we live together. The child has his fathers last name. Here is the problem, I have 2 older children who have my last name, if for some reason the father and I should seperate could I have the childs last name changed to mine? We live in Ohio

You would have to pettion the courts since the child is now recognized by this name. The father would have to agree to the name change,if he does not it will probably not happen unless you could convince the court of a valid reason. That is why is is always very important to choose the name carefully because you and they have to live with the choose. Until they are of legal age when they can change their name themslves.