Dear Jody,
You are doing the
correctCorrect (new formula) thing by having your son attend
schoolPreschooler development
Preschooler test
Preschooler test or procedure preparation
School age child development
School age test or procedure preparation
School-age children development and not indulging his wish to remain with you. This is quite important, because you don't want to reinforce the behavior by allowing him to avoid school.
Now, the unusual feature in your son's instance is that this behavior is persisting. Generally, it wanes after a number of days or, at most, weeks. It would be worth checking with the school guidance counselor and, beyond this, considering an evaluation by a pediatric mental health professional who can evaluate your son and offer you guidance.