This really hinges on what you think a fetus is. Religion doesn't have to be involved. I know atheists who think that a fetus shouldn't be aborted.
Would you tell all the mothers who have had abortions and carry around guilt and remorse that they shouldn't feel such things because they only killed off a parasite?
I'm not suggesting that my case be the end-all-be-all circumstance that every adopted child will end up in. It really does give you a completely different perspective on life when you think that your mother didn't think of you as a useless burden, that she wanted the best for your wellbeing even though she knew she wasn't the one able to give it to you.
I just see it as selfishness.
Edit: Also, I still would allow some abortions to be legal. And the morning after pill is there for the taking.