Barely eats during the night

Hey y'all. So, my son eats about 3-5 oz of milk every 3 or 4 hours during the day (I pump) but at night he breast feeds and is only on my boob for about 2 mins and then falls back asleep.. but wakes up about every 2 hours to do this. I'm slightly worried that he isn't getting enough but he seems fine 🤷🏻‍♀️ he turns 5 months on 4/3... he weighs 15 pounds... anyone else deal with this? Should I start trying to get him to eat longer or just keep doing what works?