I don't feel like the underlining issue in this debate is when does life begin. Both side get stuck up on this issue when there is nothing to discuss life begins at contraception.
This is another common imprecise use of terminology. Using the phrase 'when does life begin' leads to confusion because the two sides of the argument are not using the same meaning of the word 'life'.
Technically, there is no point at which anything involved in the process is *not* alive. The spermatozoa are alive as they swim along. The egg is alive at it travels from the ovaries to the uterus. The fertilized egg is alive, being the combination of two separate living cells. Etc. At no point did any 'life begin'. All parts were always alive, and remain alive all the way through in the case of a healthy birth.
So, clearly, the word 'life' there is being used to mean something *other* than 'biologically alive'.
Again, the more correct term would be 'person'.
The real argument being; is it alright to kill baby's (fetuses but whatever). And if it is alright why is it?
This is where the language turns highly rhetorical, as you are applying the highly emotional word 'baby' very broadly to include, apparently, a single cell with no brain, no mind, no emotions of its own, etc. Again, why aren't you concerned about all the babies you kill when you scratch your nose? Because you don't *really* think of single human cells as being actual babies; that's just your rhetoric.
And this is where the debate spins out of control if people aren't willing to stick to precise terminology to prevent these endless circular arguments.
But, in the interests of simply answering your question, I would answer: It's alright to kill a fetus before it develops to the point of becoming a person. Unfortunately, I doubt you'll be satisfied with that answer, because it refuses to adopt your rhetorical spin on things. I don't consider fetuses to be what we normally call babies (though I do understand that many people do make this equivalence; I think it's mistaken).