Studies show that the majority of women do not regret their abortions. I’ve met many women who have gone through it, some are members of my family (and one in my family already had two kids when she aborted twins, and later went on to have two more kids) and all of them stand by the decision and agree that it was the best thing for them and their families. If I got pregnant right now I would have no issues making the same choice.
Real research psychologists do not take self-report data literally. All self-report data says is what people want the world to think. It is not a measure of reality or of truth, even if it is completely anonymous, which it rarely is. (I don’t mean that people’s names are published, but that the people are seen to the researchers.) In addition, two of the articles you cited were published by groups with a bias, who then complained about the bias of some researchers. Pot? Meet kettle.
In any case, none of the three articles said “Studies show that the majority of women do not regret their abortions.” The first said that there was no very good evidence that people became mentally unealthy (after 90 days or two years) after their abortions, and that they said they were happy with their decisions. The second, from the surely neutral journal Contraception

said that the best studies, according to their criteria, and given the set of studies they started with (who knows how they selected it?) did not show “negative mental health consequences.” The third, by the well-known neutral organization the APA

rolleyes

, again only speaks of mental health problems, not regret.
So, if you want to say that studies don’t show that having an abortion makes you crazy, that would be supported. But two of the the studies you cited don’t mention regret, and the only way the other one can measure regret is an unreliable method (self-report).
The reason that people tend to believe the people who say they do regret the abortion is because it’s harder to imagine why someone would misrepresent themselves about that, and almost impossible (from a psychological standpoint) to understand why they would bother fooling themselves about it. But it’s quite easy to see why people would misrepresent or fool themselves into saying that they made the right decision. It’s not scientific data, I totally agree. But scientific data is not the only data that can be correct, and since it is now almost impossible for a person to make it through school as a psychologist and remain neutral on the issue of abortion, one might feel that “scientific” data on that subject is a bit suspect.
–Jen