18 month sleep regression or...?

My almost 19 month old has been waking nearly every night and just talking and giggling at himself in his crib. He’s not crying so I just leave him there, hoping he’ll go back to sleep on his own. It’s been taking him usually 1-2 hours to fall back asleep, which means I’m up for 1-2 hours listening to him. Im 36 weeks pregnant and sleep is already hard to come by....I’m so tempted to go in and snuggle him back to sleep but I don’t want to create bad habits, especially with a newborn on the way! Anyone else going through this? Is it a regression or something else? He does have a canine that’s about to pop through but previously he’s woken up crying if it’s teething related. Now he’s just waking to play. When will it end?

I’m wondering if maybe he’s getting too much sleep and he’s waking up refreshed in the middle of the night. He sleeps usually from 7:30-6:30, and takes a 2-3 hour nap. Wondering if I should bump bedtime later or limit nap time?