I assumed with my first labour that as soon as I got to the hospital they would do an internal. My OB didn't do any during the course of my pg. When they didn't do one upon arrival I asked why and the midwife said that it they hurt and they will do one when they feel it's a bit further progressed. when they did one, about an hour later because I wanted to know how far along I was, it really hurt - I was like flea and nearly went through the ceiling! And as I was at 6cms (slow I felt after 17 hours!) I wasn't in a hurry to have another one!