A viral cop-out

So my little guy was really sick the other night. He was tossing his cookies and was really upset by the nausea sensation. He had a low grade fever so I took him to the walk-in clinic where the doctor barely examined him and concluded he has a virus. I accepted this diagnosis without question because he's the professional right?
Well I remembered much later in the day that last winter I had seen that very same doctor. I'd had similar symptoms to my son, nausea, fever, sore neck and cough.That doctor dismissed what I had as a virus. The symptoms did not clear up in the 3-4 days he said they should, I went to my own doctor and sure enough I had a terrible infection in which anti-biotics were prescribed. That was the first round of 3 different anti-biotics to fight off whatever it was i had developed.
My question is, should I trust what this doctor says or do I take my son to his own regular doctor to make sure it's nothing more than a virus? Given this man's track record I'm not keen to trust what he says but might just wait to see how the little guy is feeling in the next day or two. (He seemed fine this morning and did not have a fever or overall pains so he went to school)