(Cross your fingers) Could Sammy finally be potty trained?

So Sammy is 3 1/4 years old and he might have finally mastered it (for the most part). For a long time he would pee in the potty usually but would sit and sit and sit and sit on the potty and not poop. Then we got him pooping in the potty sometimes but he would scream and not want to wear undies. Then we got him to wear undies but he usually had an accident each day (but would usually wake up dry overnight?)... All in all it's been an ordeal! Throughout this time I've gotten way too many comments from too many people (usually strangers!) Maybe it's because of his size (he's in 4T-5T stuff now) but some even said, I had mine potty trained by 18 months! WHO CARES?! :) That aside, I am a working mom and things happen in their own time. That said, I'm sure that we will have accidents, and this morning (after many days of waking up dry) he had a little pee in his diaper, but we're hoping that we won't have to put diapers on Sammy anymore! At least he likes the undies we bought along the way to bribe him! Wish us luck!