What could he possibly have?

My almost 3 year old son woke up with a fever of 103.2 friday morning so I gave him some children's ibuprofen to bring it down and he was fine for a few hours while he didn't have a fever but then it started going up again so I brought him to doctor and he said he has a throat infection and some chest congestion so he prescribed him tamiflu because he said there was a lot of people coming in with the flu so he thought that could be what it is. He also prescribed him some amoxillon for his throat infection. He hasn't had vomiting or diarrhea and he's perfectly fine when he doesn't have a fever. I just don't know if he's getting a fever because of his throat infection or what. He doesn't have any other symptoms. His nose isn't running or stuffy and hes not coughing. He actually just got over a bad cough about a week ago that he had for about 3 weeks because my husband and I and my son all got the flu but my husband and I had it the worst. It didn't seem to hit my son that hard. I'm worried about it being swine flu and I don't need to get it either because I'm 36 weeks pregnant.