Really? I thought about 10grams would be a good thing? My little guy lost about that, before jumping back up and over his birth weight. He was almost a 10 pound baby and they tend to loose a little. I guess every baby and situation is different. I know when he was in for his 2 week check up, they where fine with his weight and had no concerns about it. He's a formula and breast baby.
Unfortunately I don't know much but there is a breastfeeding group you can join on med help.