Potty Training

So last weekend we decided to try and see if Jackson was ready for potty training. We were very surprised to find out that he was and is still going strong!
We started on Sunday and he's been wearing Big Boy Underwear since! The only problem that we have so far is: he doesn't want to poop in the potty, so I have to put a diaper on him and then he goes. When he went to school on Friday, he had a sub and she will be there for the rest of next week, so she isn't his normal teacher who agreed to work with me while he's potty training. He did end up in a diaper on Friday while he was at school and other then that he did tell me that he wanted to wear his diaper on Tuesday and part of Friday.
Other then that he wears a diaper at nap time and at bedtime. I have taken him to the grocery store in his underwear and to a couple of other places and we haven't had an accident yet. He also told me while we were out for a walk on Wednesday that he had to go potty and so we stopped by the park and went pee pee in the grass.
I know it's going to take some time, but he is doing so good and I thought this was going to be so much harder.