Sleep regression?

Stacey • Baby Boy 12/5/2015; Baby Girl 6/6/2018, tiebreaker due October 2020
My LO has always been a good sleeper. At 3 months, he would sleep 11 hours straight. He's 5.5 months now. For the past month now, he's been waking at least once per night again. Usually around 1:30 am. Then he gets up for the day around 6. 
I never rush in when he wakes, always give him some time try to settle. When I go in, I nurse him and then lay him back down, generally still awake, and he settles back to sleep. I'm worried at this point he doesn't need the midnight snack, but has simply developed the habit, and now I'm stuck with it. However, he does eat, so I'm torn. Anyone deal with something similar or any thoughts??   Of course when I go in, he expects to nurse, but I don't want to just leave him and never go in.