The last one I had was a problem. The technician had to have been a sadist. At one point I was almost hanging by my boob. I said, "uh, could you lower this a bit, I'm on my toes". Her reply? "But I have you placed perfectly!" I've never had such a painful mammogram, I actually had bruises the next day.
I thought is was me, but a friend of mine went to the same place and got the same woman. She hurt her too. I'll be sure to let them know I will not allow that woman near me next time I go in.
eta: I've also had a couple with scary results which turned out to be fine -- but the waiting is horrible. Hang in there.