Good going! Very well done
If it was his normal WU time, I wouldn't have let him go back to sleep. That is, when it is WU time, I go into DD's room, say goodnight and give her a kiss and open the curtains. No way she is going back to sleep after that. But if you nursed him in a dark room, then maybe he thought it was a NF? That being said, odd that he went back to sleep at all, isn't it? Does this WU time work for you? Otherwise you can use this opportunity to move WU a bit later.
There's no need to worry about your supply. It will adjust to his needs. You might be uncomfortable for a few days and wake up engorged but it will adjust soon. Pumping before going to bed helps.