I just had a root canal done and because it still had inflammation left he told me to come back in a week and he would finish the rest, and put a temp filling on it.. is it normal to feel some pain behind that.. or is it because he had to inject so much anesthesia to get me to numb up.. because I had to come back is the nerve still there?

Yes, it's common to feel pain many hours after the anesthesia wears off, if killing of the nerves isn't complete yet.