How Do I Know If I Am Producing Enough Milk?

Your body should eventually adjust so that you never get hard/full/sore unless you miss a feeding. You know he's getting enough by
1. Wet diapers (while the poopy ones vary, the # of wet diapers should stay pretty constant)
2. Acting hungry at the end of a feeding. (not 30 or 45 minutes later - but at the end) If he's still hungry, then he needs more. Let him nurse again on the first side 5 - 10 minutes, then the second - to make sure you are completely empty) before supplementing with a bottle if you want.

S.

Nursed x2 to 23 lbs on the first at a year (exclusively breastfed) - and 12 lbs on the second at 7 months (He was scrawny - needed some extra food)... although I kept nursing both to - um - 3 on the first and almost 3 on the second.

if you plan on breast feeding him long term, i would try to pump when you get sore, if it isn't near feeding time... your milk production will go down if you don't release it.
I struggled with this when I went back to work. We didn't have set breaks for me to pump, so I would only get to do it once and day if I was lucky, in a ten hour shift, and then go straight home to feed him. It really cut my milk down.
Just an idea.
good luck and congrats on the baby!

Actually, if you're feeding on demand, then you may never feel full. The majority of the milk the baby consumes in a feeding is produced while the baby is nursing. As someone else said, you know the baby is getting enough by the number of wet diapers each day, if the stools are "seedy" and if he's gaining weight. In my experience, my breasts only become full/sore when I did not feed frequently enough.

I very seldom got really full feeling. Sounds very normal and as long as he is eating and quiting on his own (via falling asleep or losing interest in nursing) and he is happy and healthy and gaining weight, then you are good to go. Sounds like you are doing great!