Yes, sweetheart, it's totally Guy 2.
Don't worry about the difference between the date based on your last period and the date based on the ultrasound; the ultrasound is rules when the two disagree, because it looks at and measures the actual baby. And since you had an iffy period May 1 they really can't say when your last period even was, let alone base a due date on it. The ultrasound measures the baby and looks at its developmental markers, and when it's that early in the pregnancy it is very clear regarding the date of probable conception.
Guy number 2 conception would be in may with January 30th due date. Plus you had a period and guy number 1 was protected so least likely