1211, contrary to what many anti-abortionists think, I highly doubt that any women at all really use abortion as a form of birth control. I don't think women go around irresponsibly and think "Oh no problem, I'll just get an abortion if I get pregnant, and another, and another, and another, and another....." I think that's false thinking.
Now if some States ever get away with outlawing birth control like they want to (crazy) THEN I imagine you may see this happening.