It is possible to become pregnant even with "protected sex". No contraception is 100% except abstinence. That is fact.
Opinion: I do not believe that life is "created" by human procreation. God is the Source of life and what we humans do or don't do is not more powerful than what God has done. Life is eternal since it is a characteristic of God and God is eternal. This flawed human experience is clearly a temporary state which we will overcome at some point after freely making the requisite progress.
Human life begins with the process of birth. The environment of the womb will not allow for development beyond about 9 months. Not until the process of birth does a potential human being become a baby. Not until the process of passing years does a baby become a child, adolescent and adult.
What I am concerned about is the freedom to determine how our lives will proceed with as little interference from the corrupted power of human government. I believe that most abortions are not in anyone's best interest but some may be what is best - but that decision is the responsibility of the woman who is directly involved.
Sucking tobacco smoke into the lungs is really not in anyone's best interest and can even kill those just in proximity - but it is still legal. Try working on that if you are truly interested in a culture of life.
Ah the old let's take the most extreme possibility and use that as a defense for our position. Since contraception is only say, 98% effective then abortion on demand should be acceptable. And let me be sure I have this straight, you are saying that a completely unique life with its own DNA is not a life because the baby hasn't left the mother's womb, so that makes it alright for the mother to just flush that life down the toilet at her leisure. I will give you credit for creativity. Have you ever applied for a job as a spokesperson for PPH? I don't think they have ever come up with a argument for killing unborn children quite that novel.
I feel really sorry for someone who thinks second hand smoke is a bigger pro-life issue than abortion.