Preschool Advice

Preschool registration was tonight. I felt like crying on the way home. Not because my "baby" is growing up so fast, but because I don't know what to do! Here's my dilemma. Our preschool has 2 options: 2 full days or 3 full days. I chose 2 full days and here's why:

1. My plan is to send him through the preschool program twice. He's young and small, so my thought is that it will be better for him to be older than younger. (Pat strongly disagrees with me on that so much that we haven't talked about it in a long time.)
2. It's FULL days. If it was half days I'd have no problem doing 3 days, but he'll only be 4. That's a lot of school for a 4 year old.
3. We're broke and milk prices aren't projected to improve much at all this year. More days a week means more $$$.

Here's my problem:

1. I will student teach next spring. I refuse to send him on the bus and with milking that leaves no one to take him to school in the morning.
2. Carpooling would be an option, BUT all the other families we know and are nearby are doing the 3 days a week option.
3. All the other kids he knows are doing the 3 days a week option. This doesn't concern me a whole lot since he isn't particularly attached to any of the kids, but it would still be nice to know the families of the kids he goes to school with.

So bloggyland, what would you do?