Firstly, congratulations!
Arthur was 10lbs 5oz at birth. To be honest, he fed a lot less (it seemed) than his 8lb 7oz born sister, but I was tandem nursing when he came along, so he probably didn't have to work as hard for the milk.
Babies do vary regardless of birth weight in how much they feed. It's very normal to feel like all you do is nurse in the first few weeks. If he's not throwing up lots of milk, you're not overfeeding him. Go with it, and trust your body to produce what he needs.