I had an ultrasound done sept 19th, 2013 that showed I am 11 weeks and 6 days pregnant and another one on Oct 1st that showed I was 13 weeks pregnant. I am now 27 weeks pregnant and was just wondering when I would have concieved around? I had an affair with someone else just once on June 20th, 2013, could he be the father? My last period was July 1st I believe, i wasnt sure so thats why i had the ultrasound done.