Breastfed baby weight

For the mamas that have been doing this a while.... Do breast fed babies gain weight slower than bottle fed? At her 8 week check up, my baby was 10 lbs, up 2.5 lbs since 2 week check. Her doctor called her "skinny" and since then I've been freaking out. She feeds about 15-20 min about 6-8/ day. I let her eat until she unlaches and hear her swallow so I know she's getting milk. She sleeps and plays normally and is very active- she rolled over at 8 weeks. Should i schedule another appointment with lactation consultant?