Why is this? Why is it that, generally women hide the fact they've had an abortion, even for a good reason?

Generally they hide it for the sake of avoiding the negativity, and it's sad that that happens even in the case of ectopic pregnancy! I once tried to explain to a deeply Christian gentlemen what that was and he said something about "well I hope any woman in my life would make the right decision." My mind boggles, really, that some people are so clueless about medically necessary abortions.