You got pregnant in JUNE.
I am currently 16 weeks and 5 days pregnant from intercourse from:
JUNE 21st 2015<<<-----
I think it is pretty clear the guy from May had nothing to do with it. There is a pretty big gap between May 28 and when you would have ovulated, June 11-14 sometime, and you had a period in between as well.
8/3/2016 and it was given by an ultrasound and I had my ultrasound at 12 weeks
Hard to be sure without more information than you are giving. What is your due date, and was it given to you by an ultrasound? If it was, at what point in the pregnancy did you get the ultrasound?