Patient: A woman I had sex with told me she was pregnant. Yesterday she went for ultra sound. I’ve not had much contact with here so I don’t really know what’s going on. We had sex Oct 23 2014. On the picture of the ultra sound here LMP is Oct 26 2014. And the gestage is 15w 3d. Said her due date was still Aug 2. What’s the chance it’s mine if we had sex before her LMP?