There is a very distinctive and widly important feaature that distinguishes the two: a working umbilical cord.
That should be obvious to anyone with an IQ greater than his shoe size: Birth.
When a child is no longer occupying the body of the mother, forcibly respirating and extracting nutrients from her metabolism and injecting her with hormones and waste, it is no longer violating her rights. I'm not just repeating those facts for my own jollies, you know; it is because you are apparently incapable of realizing the significance of those circumstances. Take some time and use that fatty lump just north of your neckline to ruminate on it. Despite all indications to the contrary, I want to believe you have the capacity to understand the distinctions.
I am doing my best not to attack a strawman, so I am asking you to fully explain your position, and not trying to impart my own understanding into the framework of your argument. From the bolded, it would seem you can kill a child after birth but before the umbilical cord is cut, and call it an abortion. But, from the underlined it seems that the umbilical cord is not important, but the location of the child/fetus is the critical difference. The difference between the two arguments is small, but the difference can be very critical in some instances.
And to be clear, I think these distinctions are important to the original argument, that the mother does not owe a duty to the child, and that pregnancy is not a reasonable predictable result from sexual intercourse. The duty question is important because at some point the child changes from no obligations, to many legal obligations. And, there are some laws that confuse the issue, such as laws regarding alcohol and illegal drug use during pregnancy. These laws seem to imply the mother has a legal obligation to abstain from these substances above and beyond any normal prohibitions.
I don't understand how you can think pregnancy is not a predictable outcome of sex. Now, under some circumstances, birth control, hysterectomy, or vasectomy I understand it not being a normal outcome, but those are special circumstances that involve changing the normal state of a human body.
From my point of view our legal system does not provide a good framework to argue that it is clear that the mother can have an abortion based on precedence. As I recall Roe vs Wade was based on the privacy of the mother, which implies the fetus has no rights at the time, but killing a pregnant mother somehow justifies two homicide counts. So, when the mother wants to abort the child it is not a person, and thus it is not murder, but when the mother wants to keep the child and someone else murders it, then it is a person and can be murdered. Thus, I do not believe someone could build a logical framework to support a legal right to abortion when the status of a fetus seems to be determined according to the desired outcome instead of being based on any logical basis.
I am sure we would agree that a zygote at the very beginning of the pregnancy process is not a real human with feelings and rights. But, I am not confident that I can draw a line where the status suddenly changes, and I have never heard an argument that I consider strong as to when the status suddenly changes, even though the choice seems to be binary.