Did a tv u/s at 11wks and it gave a d/d of 7.25.14 and a conception date 11.1.13. I was w man a 10.25 and man b all days after. Which is more likely? Plz don't say paternity test I need a drs expertise

Not exact science. All any doctor can (or should) say online is that with the dates you've given "b" is much more likely than "a." since us in the 1st trimester is accurate to within about one week (+/- 3/4 days) it's not impossible that "a" is the winner - but its very much less likely.
Paternity. It is man b. But, that is not 100% guaranteed. Fresh sperm are thought not to survive six days. The limit is thought to be five days. But, your conception date is at best an estimate. And, if two men's sperm were ready to meet the ovulated egg it could be either sperm that caused the pregnancy. Thus, in reality, you will need paternity testing. That is going to be the only valid way to know.