In the recent magazine it staes that a breastfed babies should have a bowel movement every 3-4 days. I learned with my first child from her to the pediatrician that babies older than one month can go up to 14 days without a BM. Breastfed babies have less waste so its healthy to have BM less frequently as formula fed babies.
There is such a variance in what is normal for a breastfed baby to be pooping. As long as his stools are mustardy and seedy then it is OK. You would be more concerned if they smelt foul or were green, runny, and mucousy because that can mean that they are sensitive to something you are eating.
I had major oversupply with my oldest and she didn't stop pooping more than 5 or 6 times a day until she was closer to around 3 months old.