This morning when Colin got up I waited to see what he was going to do and if he would put pressure on his leg. He was very hesitant and cried at first. Chris and I basically had to bribe Colin to stand up and walk down the hall. He did, but very gingerly. He was not himself crying/whining off and on and when the bus pulled up he was really not happy. To top it off, I got a call from the nurse while I was in the middle of class and couldn't do anything about it at that moment. She said he was crying off and on and really not himself in school (according to all of them, he is ALWAYS happy at school). I got myself so worked up and concerned I called the pediatrician on her cell phone. Her immediate answer after listening to everything was hip synovitis. As soon as I saw the information on the website, it fit Colin exactly (and was one of the things I found in my research last night). It's basically inflammation in the hip that comes on suddenly and is very common in toddlers. It's basically a virus in the hip area. I felt much better after hearing that.
After I got home today he seemed better. He is still walking gingerly but it's much better than it was this morning. I was glad he was better because he was my date to the 8th grade dance tonight!
He was very overwhelmed and mostly very clingy, but he did pass out some high-fives, blew some kisses and danced a tiny bit. I know he wasn't up to par and it was pretty loud in there so we'll see how it goes next year!