Mean, Being Played, or Brilliant?

So yesterday I pick the Konman up from school and he is kinda grabbing his belly. He says he doesn't feel well. So, naturally, I ask him what he ate for lunch "Just a cinnamon roll because they didn't have the kind of bean burrito I wanted." Being the indecisive mother I am, I can't decide if he is hungry (because he normally eats a ton) or sick. So I decide the best way to find out is to feed him something. At 6:30 last night he threw up. Then I can't decide if something he ate didn't sit well or if he has this awful flu thing that is going around. About that time the pizza arrives and he says he wants some so I tell him he can have 1 piece and some applesauce. Isn't pizza on the B.R.A.T. diet? After one piece the poor kid is starving so I let him have another piece. At bedtime his stomach starts to hurt again. I sent him to bed with a pitcher and he made it through the night. I fed him oatmeal for breakfast a bit earlier than normal, hoping to see how he reacted to it before I sent him to school. Everything seemed fine until right before we leave for school. Then the following conversation takes place.

"My stomach hurts."
"Like it was last night?"
"Yeah."
"Do you think you are going to throw up?"
"Yeah."
"Well, I can't send you to school if your sick."
"Oh, I was just kidding?"

After a few tears about not getting the perfect attendence award and "I said I was just kidding"
I told him I didn't know what to believe and I can't take a chance sending him to school. Then he was like OK and he's been playing just fine all morning. So I sent him downstairs to clean his room. I'm starting to feel like I've been played, by a 1st grader. I'd like to think I'm smarter than this. I mean if he can fool me now there is no hope of winning in the future. I can't decide if I'm mean for making him stay home and clean his room on a "sick" day, or if I've been played(by a 1st grader), or maybe I'm brilliant for figuring out I got played(if I did) and making him have no fun by cleaning his room. All in all, I think I'm putting way to much thought into this chess match and I need to save as much mental capacity as I can for the next one.