K.C.
I applaud you for introducing the potty early on!!!! My first 2 children were basically potty trained by 2, 2 1/2. My third, who is 13 months, already poos on the potty. I don't quite understand why society has this stigma that 3 and 4 is the normal age to potty train. Who the heck wants to change diapers for that long!, and then have a battle on your hands with a toddler! Ah!
As for your son, it sounds like he is doing great! My daughter, who I started at 12 months, didn't actually consistently tell me she had to go until about 2 1/2. But there was no battle, no emotional fallouts, no tantrums, and No Bribes! It was just what she knows to do. I think it sounds like your son is doing Great and he is right on schedule. I think you need to continue asking him, and putting him on the potty at certain intervals.
The ball is in your court, and it might be a few more months until he is able to go on his own, but what a great achievement that will be!!!
So my short answer is have a timer if need be, and put him on the potty often.
Yea for you!