I'm not sure of the size, but I can tell you that EVERY child goes through the "I don't wanna" phase. All of mine did it and I have been in daycare enough times to see other kids do it as well. Once he gets used to it there and more comfortable with the routine he should settle down.

I know I've said it a few times, but I am so glad that you were able to adopt him. Congratulations Mommy.