I see no one has considered that fact that if the OP had abstained from sex altogether, he would never have this problem. I see no reason why people are even prepared to take a life yet they knew having sex is meant for procreation not simply a pleasurable experience. So I am saying that complaining about it is pointless as you reap what you sow, for both future parents.
As for question of when life starts in the womb, it is the day the egg is fertilised and it becomes a zygote. That is from a physiological point of view