Hi,
That sounds perfectly normal. There's a growth spurt around that time, and the little ones will nurse _a_lot_ right around then. It's not unusual for a baby to cluster feed either -- a bunch of feedings very close to each other for an hour or two and then a longer time between. Nursing a lot like this stimulates your body to produce more milk, which is needed for the bigger baby. I would let your baby nurse for as long as your son wants -- not just 10 minutes. During a growth spurt, there were times when both my children would nurse, going back and forth between sides, for an hour or more. I found the sling very helpful during these times because it left my hands free and I could move around a bit.
Most importantly, I wouldn't worry much about your son eating too much. Babies, especially at this age, really won't overeat -- they eat what they need to grow, and it increases steadily. If he's gaining weight, which is easy to determine, then you've got nothing to worry about.
Congratulations and enjoy your son! These first days are over far too quickly!