A rose is a rose is a rose. Killing innocent life is wrong. Final benefit is not a mitigating defense for murder.
Isn't it interesting that we don't divide up what constitutes life in the animal kingdom. If I break a Bald Eagle's egg, it is considered the same crime as killing the Eagle. Curiously, what is the difference between a fertilized egg and a day old baby in your view? Neither one is salient or viable if left alone.
If you slaughter your pig, it's legal. If you slaughter your neighbor's pig without permission, it's not legal.
If you destroy a fertilized egg that's your own, it's legal. If you destroy a fertilized egg that's not your own, it's illegal.
Is that concept difficult to understand?