Pregnancy-whos the father?

Patient: My LMP was 10/22/14. I have a 32 day cycle. I slept with my current bf from 10/25 to 11/13. We were trying to get pregnant so we were using the clear blue advance ovulation test. Which says my Lh surge/ovulation was nov 9, 2014. However on nov 15,2014 I was involved with my ex and stupidly we slept together. He used the pull out method, it was a one time deal, so no sex after he had ejactulated and there was no ejactulation before sex. I had a positive pregnancy test come back on 11/25/14. Doctors are putting my due date at aug 6. If they go by my last period my due date should be July 29, however they are telling me the baby measured a week off and I probably ovulated later then I thought. They believe I ovulated on Nov 13. I’m just trying to figure out if there’s any possibility that my ex could be the father. I understand the mistake I made but I would prefer to have an idea sooner rather then later.

Symptoms: None