DS was born 50 for weight and 75 for height.

He's now 9th for both - or was in June when I last had him weighed and measured. No worries here. DH and I are both slim, so DS obviously is. We've all seen DS run around so he's burning off energy, they do check he eats. Bit more worried about the height; I'm off the top of the girl scale and DH is 75th on the boy scale (adult, age 18-20, in the baby books). But DH was a midget then just shot up, as did a cousin of mine who is now 6'4 so we're not worried about that too much either. Just so long as he puts on weight and grows and we're not starving him (ie he has loads of energy) then it's fine.