I'd just wait. But that all depends on you & your tolerance level. I much preferred changing diapers to cleaning messes. Other moms hate their child being in diapers more.
My son didn't potty train till 4 1/2 and *to me* potty trained means going to the bathroom by himself, without wetting or without having me DROP everything I'm doing right this min to take him to the potty.
4 1/2 seems rather late (esp when moms of 3yo or younger boys are saying theirs are potty trained) but one day I was out with a friend whose son was "potty trained" and both boys were approaching 4 and he made a mess in his pants. She went into the restroom to get him cleaned up but had nothing at all for him since his underpants and shorts were dirty (I had a diaper in the car) so the rest of the time we were playing at the fastfood playplace, he was in a diaper which he hated but it was either that or be naked.
That is when I decided not to be in awe of young potty-trained little guys because MOST of the time I found it to mean they were potty trained in going pee in the toilet but would still go poop in their underpants. and/or still have nighttime accidents. I prefer to deal with poop in diapers or toilets, not underpants!
The # 1 guideline I see for deciding readiness is does your son wake up dry each morning and then go on the toilet? Go by that, more than anything else.