When my daughter was 3 1/2 was about the age we started to go without pull-ups at night. We would take her potty before her bedtime and again before we went to bed (about 10:30).We'd just carry her or lead her to the bathroom. Some nights I don't think she ever actually woke up! I do not/did not want to stop liquids... if my kids are thirsty, I want them to drink.
The first couple nights I double folded about 5 beach towels and put them on her bed, so if she did pee during the night, I could just take those off and not have to change the sheets. The wet never went all the way through. She only had 2 accidents that first week and none after that. We kept taking her potty for about the next 6 months before we went to bed.
Now, she's 4 1/2 and gets up on her own if she needs to go potty. If your son comes to your bed, the first thing I'd do is take him potty! If he doesn't stay dry all night after 2 weeks of this, I'd say she still sleeps too soundly to go without a pull-up. Lots of kids aren't nighttime trained until much older.
That said, my son potty trained before he was 2(!?), but I don't expect him to be night trained for quite a while. He's nearly 3 and wakes up with a very soggy diaper every morning!