Hello...looking for some advice.

My son turned three in October and has shown no interest in using the potty. He showed brief interest just before turning two, but I decided to let him lead on this and not to push, and I'm not sure that was the best decision, b/c we are really struggling now.

I'm still trying to let him lead, but he starts pre-school in the fall, and honestly, I'm just really tired of diapers. I feel like I need some kind of strategy. I've tried stay home days where I set a time and take him to the potty every 20 minutes, but he will not go and then goes in his big boy undies. I've tried offering rewards like chocolate chips, but it makes no difference. I don't want to push him, don't want to discourage him, don't want to battle over this, but shouldn't we be making some progress by now?

He also got the Peter Potty urinal for Christmas, but it hasn't helped.

Thanks for any advice and/or reassurance that I do not need to stress over this.