A couple of things about potty training...first he's 3. He might be a bit young to start pulling him out of the pull-ups at night. Work on being dry during the day when he might actually have more control over it rather than when he's sleeping.
Secondly, try to relax about it. This is the one thing he has more control over than anybody else. And my next door neighbor who has twin boys were wearing pull-ups closer to 4 too. Even my daughter was wearing them around 4.
We pretty much tried to relax until we were sure the comprehension was there. When we were sure we mastered being dry during the day (she still has accidents because she doesn't want to take the time to "listen to her booty" as she says and go potty), we kept buying the same size pull-ups even though she was out-growing them. After a few nights of complaining that they weren't comfortable and she wanted to wear her regular panties, we told her, "That's going to mean paying attention and if you wake up in the night, you have to get up and go potty." She announced, "I go potty in YOUR BATHROOM!!" I told her I didn't care which bathroom she went potty in as long as she got up and went potty. That worked pretty well.
You could also use the "timer technique" in setting the timer for 20 to 30 minutes, and when it rings, it's potty time! We used that in combination with the "potty first" rule. Anytime she wanted to change activities or have a snack or get a drink, "Potty first". That way you make whatever they want be the reward. Usually they're doing that because the position they were sitting in became awfully uncomfortable because they had to go potty and don't want to take the time to do it because it's boring. Nobody "likes" to "have" to go potty...it's just a fact of life.
I would invest in a waterproof matress pad. There will always be nights when he's "extra tired" because he had a full day of activity, and might not wake up in enough time to go potty.
FOr what it's worth - and good luck!