Help! Should I reg my son for pre-K?

Meech

My son turns 4 at the end of August which technically makes him old enough to attend pre- kindergarten. I myself feel like this is just too early for him. He's only going to be 4 for a few days before they start. All of the other kids in the area are being signed up but they are all at least 5 months older than my son. Which is alot of growing for a little tyke! He's also never been away from loved ones for more than one hour as he's watched by my mom when we are at work. I've asked our family doctor and he feels pre-K is more like glorified babysitting and thinks he's too young. I'm being pressured by family because everyone else is enrolling their kids. You can send your kids for a few days or the whole week, class runs from 8-2:30pm. I just feel like he's only a toddler still and that he's still a little young. Am I crazy? 🙄. Anyone else in this boat?