The answer depends on whether the father has been adjudicated as the father. You should call an experienced family law attorney in your state and ask if there is a law to prohibit you from leaving without his permission. In MN there is a law that says you cannot leave the state without the father's permission or a court order if the father has parenting time rights under the law. Find out before you leave or you could find yourself facing a court order giving him custody. Good luck.