You can draw a line wherever you want with regards to terminology you prefer. Calling a fertilized egg an unhatched chicken would be totally reasonable in my opinion, though an unfertilized egg meant for cooking isn't a chicken at all.

I'm sure there are some people who have a ceremony or funeral after a miscarriage, why is that a problem? Going through a miscarriage is extremely traumatic, especially later in the pregnancy. Who the hell are you to say how someone can and can't grieve?