You don't mention the name of the state where your ex- currently resides, but most states do not based jurisdiction or venue for a paternity suit on where the child was conceived.  It is determined by the residency of the child.A custody suit at this point would be premature because the child has not been born yet.  Your ex- would have to wait until the child was born and then file a paternity suit where you live with the child. So, considering the rules of venue, jurisdiction, and timing of a paternity suit--- the only thing that you need to focus on right now is having a healthy child.  He cannot make you move back and have the child where he lives.  If he does file a paternity suit where he lives after the child is born-- you can have the suit dismissed for improper venue.  If there needs to be a paternity suit, either of you can file it in the state you live in now.  Considering that the child will be a new born, you will have a very good chance of retaining custody because courts do not like removing new born children from mothers--unless there is a very good reason.  Reasons could include the mother or child testing positive for controlled substances after being born. Absent some poor conduct on your part, you should not have to worry about keeping custody.  So stay focued on what is healthy for you and the baby and let your ex- just stew in his own state.