I had the N400 interview today at Newark. The officer told me the petition was approved and told me to wait for Oath. Then later on told me they can't swear me in today. He said I will be called for oath in a month. Is this normal? They were running very late. I had a 1 PM interview time but the interview took place at 4:15. I was hoping to take the oath today itself. If anyone had this happen to them, how long was the wait for oath appointment? Do they send any notification prior to oath saying the petition was approved? Thanks.