By now, he's probably over this. If not, he may be too young to tell you he needs to go. If you think he's ready, reward him with a sticker when he asks you or goes on his own.
I have a 2 1/2 year old who can stay dry all day if I bring him to the potty every 2 hours. If I wait for him to ask he will go in his pull up. How can I get him to ask me to use the bathroom or go on his own?