Chinese Dragon, thank you for explaining yourself (quite eloquently, more so than the average 35-year old) and your situation. I grew up Catholic, too, although my household was pro-choice, so I just had conflicting things stirring within me when I was 15. I remember having someone come to our CCD (aka, Sunday School, not on Sunday) and show us the horrors of abortion, and feeling very conflicted.
For the record, I think you have EVERY RIGHT to believe what you believe. It's a totally viable viewpoint. Like came up earlier, for instance, killing animals for food. I see why that bothers others, but it doesn't bother me. I have a line drawn where others don't, and it's as solid an opinion as mine is. We all get heated up about abortion because it is, well, sensitive, and many people have personal experience with it, and others don't, but have a strong moral idea about it. Like, I don't believe in the death penalty morally, but if someone killed my child, would I want them dead? Hmmm... Don't know.
Not to say the situations are the same, but I think abortion is an argument that goes around in circles because each side is arguing a different issue, and yet everyone is intending the best for society (well, usually, but in this thread, yes). I live in the San Francisco area, and grew up in the Boston area, so also, my environment was totally different than others. Anecdote: my ex-boyfriend from Oklahoma came to college in Boston and would wear a Pro-Life tee shirt in public, and he didn't understand when I told him he might get beaten up, because in his environment, it was totally cool, like saying, "Go Green!" or whatever, but it Boston, it was a RED FLAG.
Anyway, I don't discredit you for being 15; I credit you and respect you for your intelligence and your eloquence and your integrity. Keep it up.