Usually they gain more quickly as that is a growth spurt time. Kelly mom has a chart that shows ages and what weight gain should be for bf babies.
DS1's weight gain did slow down at about 3 months, and it turned out my supply had dipped. I worked with a lactation consultant to pump, add extra feedings, etc, and within two to three weeks, DS1's weight gain was back on tack.
Did your Pedi think the wright was low?
I agree working with a LC would be good. Initially, we worked w/one that was part of our pedi practice. It was not a good idea for us to mix the two. My son lost more than 10% so more of our time initially was spent on getting his weight up and less on LC which resulted in a rocky start to bf'ing. Feeding is well established for you so it won't be another factor to juggle. I found it beneficial to work w/ an independent LC not affiliated with our MD. Maybe it was just a fluke for us, but I wanted to share.