My wife and I had sex twice in the month of November. She was using the nuva ring (used it right) and I used the pull out method. In Novemeber her period started on the 12th and in December it started on the 12th. She told me that her period only last 2 days. We are currently going through a divorce and she says one minute shes not and the next she is telling me she is pregnant. What are the changes of her being pregnant?