Hi! This was a concern of mine recently, too. I did a little research, and even the Christian Medical Association has determined that there is no evidence that hormonal birth control methods prevent a fertilized egg from implanting. Think about it.... how many people have you heard of on birth control who got pregnant anyway? And how many continue taking their birth control for weeks before realizing they are pregnant, with no ill effects to the baby? (Not trying to change your beliefs, only give you a little more info....) Anyway, the best method I can think of for you if you truly don't believe in hormonal birth control would be the copper IUD (it creates an environment toxic to sperm) OR the tried-and-true condom and spermicide. I think barrier methods are the only ones with a guarantee not to harm a fertilized egg, although they are also the most unreliable. Good luck!
The pill or any other kind of birth control does not kill a fertilized egg, they prevent the egg to become fertilized. When ur on the pill, the pill makes ur cervical mucus more thick so it makes it harder for the sperm to reach your eggs.