Milk per feeding

How do you know if kiddo is getting enough milk? Like when I pump throughout the day I only get like 1 oz per side during his “feeding times” but he eats 2 ounces from bottle per feeding… does that mean he doesn’t get enough milk if he only Breastfeeds on one side? Cuz he doesn’t fall asleep when breastfeeding,right after breastfeeding, but he won’t latch onto the other side to continue nursing… im confused