Only a very small percentage of people use birth control every time they have sex. It is in our natures to take chances. That doesn't make us stupid, selfish, irresponsible or hedonistic. That makes us human. At the same time, the options available for birth control are highly inadequate.
Most women voice their fear of pain as their greatest anxiety around the abortion experience.
In fact, most women comment that it was far less painful than they feared and was finished much sooner that they expected. My dentist recently had to fill a cavity in my molar. I was crying from fear and pain as she injected the anesthetic. My announcement that I would rather have an abortion than a cavity filled shocked her into silence. Some women experience abortion as painful.