Is today over yet?

So, my Tuesday was pretty good after subbing my first day and everything, but Campbell's wasn't very good. After having 2 great weeks at preschool, week 3 started out very badly. He's getting some huge monster teeth in the back, and he didn't feel very good at school. He cried most all the day--didn't even eat his lunch. Those of you who know him well know that it is serious business when campbell doesn't eat. Then that afternoon he had a sort of blow out diaper, and I thought, yep, it's those teeth. Wednesday he seemed to feel fine, but had another questionable diaper. But he slept good Wednesday night, and he ate a good breakfast Thursday morning, so I didn't feel bad about sending him to preschool. Well, in the middle of Walmart around 11:00 today, I got a phone call from preschool. They said he'd been crying inconsolably since he got there, and they didn't know what to do.
They were great. They told me it was up to me, that they were fine to try and asuage him until 2:00, but since I had that lingering question of how he was feeling in the back of my mind, I decided to just go get him. As soon as I got there he calmed down and started saying, "Mommy's car!" I asked him if his teeth hurt and he said no. Asked him if he felt bad, no. By the time we got home, he was happy as could be. Looks like Mommy just got played. It's just one of those parenting decisions that you just don't feel good about either choice. I didn't want to leave him there and get home and him have a fever or something. So, I've been second-guessing myself for the last 2 hours. But we talked and I told him that he was definitely staying at preschool on Tuesday. I guess we'll see how that goes. Any advice?