I have an outrageously good 3 month old baby. He's a good sleeper, never cries without reason, loves cuddles and going outside. He's EBF, and we feed on demand. He's happy and smiles all the time, he has lots of wet diapers in a day and poops once or twice a week. however, the pediatrician thinks he doesn't weigh enough. he is a pretty lean kid, but I think he just has his father's fast metabolism (darn it!). I don't want to use formula if it's just her opinion (even if it is professional). Breastfeeding was a difficult journey for us and I don't want to give it up. Of course if supplement if he really needed it, but I'm not sure he actually does. thoughts? Update: birth weight, 7 lbs. 5 oz, 20 1/2 in. long, at 3 months he's 24 in. long and about 10 1/2 lbs. may be a few oz. les