How often does your baby nurse?

My baby is almost 5 weeks old and he wants to eat all the time. If I can hold him to every two hours I'm lucky, but usually he wants to eat every hour and a half. This has been going on for the past 2 1/2 weeks. If it's a growth spurt, isn't it a little long? Prior to this "spurt" of whatever it is, he'd stretch his feedings to every 3 hours and that was great because he'd eat for a half hour and then I'd be free to do other things. Now, however, because he eats so frequently, he only eats for about 8 or 10 minutes at a time and before I know it, it's time to eat again. Is this normal for a newborn? How frequently does your baby eat and for how long?