A fetus does not have a 0 percent chance of survival, inaccurate. A fetus will survive as it continues development in the womb and then post birth.
By that argument, an egg cell does not have a 0 percent chance of survival either. It will also survive if it meets the right conditions in the womb.
If you then claim that an unfertilized egg cell isn't a human but a fertilized egg cell is, the only different between the two is that it has gone from 23 single chromosomes to 23 pairs of chromosomes, meaning that a skin cell is also a human. We can also remove the nucleus from a skin cell and put that in the right conditions in a womb and grow an entire individual from it.
Your cut off is entirely arbitrary. A ball of cells is not a human being.
Consciousness doesn't even exist for babies post birth.
That's just not true. They can sense their environment, they can react to stimulus such as bright lights, pain, or skin to skin contact, they can communicate that they are hungry or tired, etc. A fetus before the limit of viability cannot do any of that because it does not have a functioning cerebrum.
No pain, you won't be aware of it, and you were consciousness for it either. For the same reason why abortion is unethical. You deprive someone the privilege and experience of human life.
I've already addressed this. Being temporarily unconscious is not the same as having no capacity for consciousness because your brain has either died or doesn't exist.