Well if it has a "right" to life, then it has a legitimate moral claim to continue living.
There's not much difference between a fetus in the early stages and a complex bacterium. Neither can feel pain, neither are self-aware, etc.
http://news.bbc.co.uk/2/hi/health/4905892.stm
I don't know that fetuses can "experience" pain.
You "wouldn't allow" your wife or girlfriend to get an abortion? Why is this, and how would you prevent them?
Take this analogy:
"Let’s say the Society of Music Lovers kidnaps you, and hooks you up to this dying violinist. If you choose to unhook yourself, the violinist will die, but if you let him stay hooked up to you to use your kidneys (for a period of nine months), then he will be cured and both of you will be free. Thomson asks what a person’s obligations in this situation are, and, to be consistent with Warren’s argument, she says it would be ridiculous to be stay in bed with the violinist, and thus you are able to leave at any time. You shouldn’t feel responsible for the death of the violinist."
I would count that as similar to rape. The baby might very well be innocent, but the mother is hardly responsible for keeping it alive, just as you are not responsible for keeping the violinist alive.
Why does a fertilized cell have rights?