I'm expecting a baby in September, and the fact is that come afternoon, when he would be in kindergarten, I will be too tired to provide the stimulating environment he seems to demand. He's also been to preschool three mornings a week. They don't offer afternoon preschool programs where we live. Any suggestions?
You could decide to let your son start kindergarten, knowing that you might let him repeat the grade for the next year. Research shows, however, that retention greatly increases the likelihood that a child will drop out when he reaches the legal age to do so.
Visit the school your son will attend and talk with the kindergarten teachers. Talk also with some of the first- and second-grade teachers, and find out what their experience has been with children whose birthdays fall just before the cut-off date. They will be able to tell you, in terms of the curriculum followed by that school, how successful younger children can be.
Your concern about your own physical ability to keep up with your son after your baby is born is a valid one. You mention that the preschool is three mornings per week and the kindergarten program is in the morning, so either way afternoons are going to be a problem. Is it possible for your son to go home with a friend or a classmate two or three afternoons a week during the fall? That way he could have fun and be stimulated while you could still get some rest.