Exams and Root Canals

Has anyone had a root canal? I had to have one a few weeks ago, and while it wasn't painful during the procedure (they gave me so much Novocaine my face was numb up to my eyes), it hurt very badly afterwards. Root canals are done in two stages, so I go back for the second part tomorrow.

To anyone who's had one: What should I expect? Will it hurt as badly afterwards as it did the first time?

This came at a particularly bad time, right before exams. Ugh. At least my biggest exam is nine days away.