baby is 15 days old today. he weighed 9.3 pounds at birth and today at home on the mechanical nursery scale he was 7.5. he nurses well and often. he's not been to see the dr yet and i can only imagine what they would say. should i be concerned about the weight loss? should i give him some formula? any advice would be great!! i just don't want to do wrong. this is my 7th child, but the first time we are trying to do things a more natural way.