2 month old weight

My son turned 2 months on December 28th. I just had his two month checkup and he weighs 12pounds 5 ounces he’s in the 44th percentile. His pediatrician said to come in for a weight check in 2 weeks. She mentioned something about supplementing if he’s not getting enough. How can there be a way for my son to get enough breastmilk? I feed him every two hours on one breast, should I start offering the second breast after he’s done with the first? I know fed is best but I really want to stick with breastfeeding for as long as I can.