Here's a thought experiment. You rush into a burning building to try to save anyone stuck inside. Once inside you realize there are 10 fertilized eggs at one corner of the building, and a 2 year old girl at the far end. You only have time to save the 2 year old, or the fertilized eggs.
Which do you save? Now ask yourself if a fertilized egg is the moral equivalent of a 2 year old.
An interesting idea...however maybe it should be, A pregnant woman in one corner of the building and a 2 year old in the other which do you save.
A fertilised egg separate from a human body is also very different to one inside it's mothers womb.
I see where your going....I agree in principle but disagree with the premise here.