I am going to be getting married to a soldier who is stationed in North Carolina. I currently live in Massachusetts with my four year old son. I was never married to his father, we have never been to court, and his father has never given me child support for him in his four years of life. I know because of the following reasons I already have sole physical and legal custody of him. However, is there a possibility that I could be held back from moving with my son if his father decides to take me to court?

If you have never been to court then you do not have sole legal and physical custody. He does not owe any support since you have never gone to court to ask for any. He could throw a monkey wrench into things by filing for custody and visitation.

However, unless he does go to court, then you are free to move.

Agree, you are just the parent, there has been no court action, there there is no sole custody determined yet.

If the father is not on the birth certificate, then he is not the listed father yet, if he is on the birth certificate, he has equal rights to you at this point. I did not see in your post if father was on or not on the birth certificate.

As long as the bio father does nothing, there is no issue.
If the bio father files in court for visitation or custody of the child, he can ask the courts to stop your move out of state. So yes, there is court action he can file to stop you from moving.

When my wife and I divorced, I had custody of my son, but I was not allowed to move more than 25 miles without court permission, because of her rights to visit. That was in the court order.

So yes it is very easy for him to get a court order restricting. He will have to explain why he has not visited the child in all these years ( if he has not visited)

If there is no child support order in place, he owes no child support. So that is not a issue at this point.