Thanks everyone. As soon as I got to the exam room, Sky jumped out of his carrier and started purring. He acted like he was perfectly fine. His temperature was a little below normal and the vet said his chest and lungs sounded fine. He did sneeze a little bit while he was there so at least the vet didn't think that I was making this up.

Since he had a similar episode last year, the vet has put him on clavamox for the next 7 days but it's only 62.5mg 2 times a day. Last year he was on 125mg 2 times a day. He said if he's still having problems then he'll do a culture. It could be just allergies or even asthma but he'd need to take x-rays to rule this out. As soon as I got home,he started sneezing even more. Maybe he's allergic to his new brother and sister because this is the only thing that's new around here. LOL Whatever he has, I caught it early so hopefully the meds will clear him up.