More information is needed to answer that question.
Under N.C. Law, for you to have custody both the mother and your son would have to be unfit or have acted inconsistent with their constitutionally protected status as the natural parent in order for you to be granted legal custody. If that is the case and there is a temporary custody order with no on-going litigation, a temporary custody becomes a permanent order after one year. You may already have a permanent order and not know it.
But all of the above is based on Chapter 50. If you have a Chapter 7 Order, things are different....
Without more facts, I can't give you specifics. If you want to seek help from our Virtual Law Office, I have posted the link below. Best wishes,