Pitocin contractions vs normal contractions

Kate
How much of a difference is there, pain wise? I was induced for medical reasons with both my boys... no reason to this time so I'm scared I won't realize it's the real thing.. all I know is pitocin induced labor! Is the difference that big? Or no? I have quick labors (6 hrs and 5 so far) & really don't want to get there "too late" for my epidural.