First, as I mentioned before you keep discounting time.
Time has nothing to do with what something IS! Time can measure the development of what something is, but it doesn't change what something already is. At point of conception, an egg stops being a clump of cells, a sperm stops being a blob of material, they concept human life. The process of human life
begins at that point, and it continues until it is terminated or dies naturally. Time can measure the process of development, but it doesn't change what is.
Second, you wrote, "But the fact is, a fetus is already a human being, it doesn't require anything else to become a human being,...."
Yes, it does. It requires the use of another body (that of the woman). Repubs/Conservatives/Right Wingers are adamant about human beings being individuals, yet, when it comes to embryos/fetuses they are anything but individuals. It can not survive without the use of the body parts of another human being.
I'm not talking about a baby requiring feeding or an injured person requiring assistance. I'm talking about the use of another human being's organs and blood. I'm talking about living inside another human being's body. To say such an entity is a human being is taking the definition of "individual" and making a pretzel out of it.
It doesn't require a human body to be a human being, it already IS a human being, it requires a human body to incubate it to another phase of development, but it is a human life, the mother's body doesn't make it that. Newborn infants require 24/7 care or they will die, how are they any different than a child in the womb?
Again, you point out that this "entity" is living, which I ask you again, what kind of living organism is it, if not human? As for individuality, it has its own DNA, it's own heartbeat, it's own genetic code, and it is precisely how every individual on this planet began life, so how is it not an individual? How can you continue to support an argument that it's NOT an individual, in every sense of the word?
Simply stated it requires building blocks that the mother provides through her blood and use of her organs. To claim an embryo/fetus is a human being and in turn deny a woman the right to remove it from her body is nothing short of the woman being a slave. Her body is owned by some one/thing other than her. The entire concept is repulsive. We may as well throw words like "individual" and "freedom" in the garbage can.
Biology tells us it is a human being, it can't be any other form of living organism. It is not a "claim" it is a biological fact of the matter. You've presented NOTHING to refute this, and you can't. Indeed, it is currently legal for a woman to choose to terminate the life of the human being residing inside her body, it is done by the process of termination called abortion. The ethical question is not "ownership" of the woman's body, it is whether the woman has a moral obligation and responsibility to the human being she made the choice to create inside her body, or whether she can avoid responsibility by killing that human being.
As for the chicken/egg example comparisons/examples are used by logical people in order to evaluate things. We compare. That's how logical people come to logical conclusions.
But you are comparing things that don't apply. A chicken egg is the same as a female egg. Women discard an egg every month during menstruation naturally. No one is opposing that, no one is questioning that. If we were discussing that, you chicken egg comparisons might be valid, but that isn't what we are discussing. Humans and chickens have different systems of reproduction, so any further comparisons are just not valid on any level, and the morality of daring to compare humans with chickens is fairly disgusting in itself, so we can dismiss your entire argument for being completely irrelevant.
How do we know a house is a house? We know by comparing it to other things we call houses. How do we know a car is a car? We compare it to other things we classify as a car. How do we know an embryo/fetus is not a human being? We know it's not because we know an egg is not a chicken nor is an acorn an oak tree.
We know a human fetus or embryo is a human being because it can't be any other life form, and it is indeed some form of life. We don't have to 'classify' it as something, because it is human life, we already established that at point of conception, it is in an early developmental stage, but there is no disputing what kind of life form it is, or if it is living. You seem to want to think it isn't a human being because you can't see it... so is it okay to wrap someone in a blanket and shoot them in the head? Is it not murder if we do that? Did we not really kill a human being because we couldn't see them?