so my LMP was 2/18/14 and I thought I have ovulated around the March 1st and would be she 11/25. I test postive on a HPT April 4. Went to doctor did ultrasound and they told me I had ovulated later and due date 12/14. But what I need reassurance with is, who's it might be. On the 15th of March I was with a guy but never had sex with him at all, and pretty sure he never came in contact with me down there, and then on the 21st I had unprotected sex and guy didn't pull out, (doc said I ovulated the 22nd so been thinking the baby is this guys) but then had protected sex on the 26. Went in around 17 weeks to figure out gender, and baby was measuring all sorts of measurements from 18w to 20w.... I always thought it was guy from the 21st but now I'm not too sure. What do y'all think? I'm concerned because the measurements were all over the place when I found out but doc said they were right on track to be due 12/14 I've told guy on the 21st that it's his and he believes me but it's bothering me so much.