about my baby's paternity pls help.?

Do you understand how gestational ages are calculated?

They do that, 1. from the ultrasound, and 2. from the start of your last period. (They do not calculate this based on when you had sex.)

So, in July, they gave you the age of seven weeks from those pieces of information = from May 28 to July 24 is seven weeks. If the size of the embryo had been too big for the age from your last period, they probably would have questioned you about the circumstances.

Also note that most women ovulate about two weeks after the start of their period, so your ovulation date was probably about June 10.

Given all that, and given that you used a condom on May 18 and that you had a period after that, it seems almost certain - like 99% or more - that the second guy is the father.

Eventually, if you really need assurance about the paternity, you could get a test. But for now, I guess any expert would say the same things I do.

BTW: I saw that you asked this question several times and also spammed it into someone else's question, plus you answered yourself once in an attempt to communicate with one of your answerers. You may want to look into how to use Y!A a bit to see what the rules are, and to see how to add details to your questions.

HTH.