L.L.
You don't say where in Il you live but I have my daughter in a very good preschool with several locations and one of the things I really appreciate is that they do not have potty training requirement but will work with you to get there. I also have to say I think being with other kids and seeing them go potty is a very motivating factor. Keep in mind 3 years old for boys are also considered early for being potty trained and he just went through a major change with the move and might be holding onto the only thing he has any control over. I would start putting him in underwear and make him help clean up. Don't yell or punish, it does not make any difference. With my daughter I found a set of little dolls she really wanted and she earned them. One for going potty twice, the second for staying dry all day, the next for gooing poopy ect. It worked because she felt a sense of accomplishement. Good luck and know this, I have yet to see a normal kid go to school in daipers. He will get there even if it will feel like forever to you.