2 1/2 hour nursing session?

I was just wondering if this was normal. I have a one week old who has lately been eating more often than she had been (I think it's a growth spurt) but this evening, when feeding her, instead of her usual 20-30 min feeding, she wouldn't stop eating for 2 1/2 hours! If I pulled away and tried to rock her to sleep, she would just cry more, and make the motions of wanting to be fed. She was spitting up a little sparatically through out this, but not a whole lot. After she was finally done, I expected her to conk out and sleep hard, like she usually does, but I couldn't get her to sleep for another hour... she was content to sit in her bouncer or to cuddle, but just not sleepy. I'm not worried about her staying up, but I am worried if there is something with the feeding time? If it persists, of course we'll visit the dr, but I was just curious if that was normal for a possible growth spurt?