Good points, but I didn't understand one part. So if they use all that protection, and still get pregnant, they should or shouldn't? And I would hate for someone to live life with something like Down's, so I agree with aborting it then. And I never thought of the man in the situation... I would be mad since I do want a kid, but it was unplanned... So if my girlfriend or whatever didn't want the kid, and I did, who would get the last decision, even if I did have paperwork (no, I'm not saying I'm ever going to be in this situation, but you never know...)? And I also agree with the last part; who are we to say what others can't do, other than like not murdering, stealing, the stuff that we know is bad?
What I am saying is that, if a woman has done everything she can to prevent a pregnancy, whether it is one, or multiple layers of protection, then it isn't fair that she have to suffer through a pregnancy that she took steps to prevent. She should be able to choose as to whether or not she wants to keep it.
As for your other scenario, if you want the baby, and she doesn't, then while, the final word is still hers, You can go a legal route to prevent her from aborting it.. and where if she did so anyway, then there would be harsh consequences. However, I would think that if you desired the child that strongly, even though she did not, then it wouldn't be right for you to then go after the mother for child support later on, and that you would make sure that she is relinquished of her responsibilities as a mother to that child before she gave birth to it.
Seeing as how, you forced her to give birth to a child she didn't want, and would have terminated had you not have intervened. Pregnancy is not only time-consuming, and a miserable time for many women, but it is also very risky for both the mother and child. Barring external conditions like the increasing homicide rate among pregnant women, at the hands of exes, current husbands or significant others, or, crazy ass women who either lost their kid and never dealt with it, or because they are just evil, killing these women and cutting their babies or fetuses from their mother's womb to claim as their own.
There are a lot of health risks involved, such as elevated blood pressure, and heart rate, obesity as well as the possibility of death during childbirth. So, if a woman is considering terminating her pregnancy, then she has to consider these factors as well. And if she is forced into carrying a child that she never wanted, and tried to prevent, then she is forced into these health risks as well, which may result in her either being stuck with the child for the next 18 years, because the guy swore that he'd be there, and then bolted, or being financially responsible for it.. because the guy decided to force her to be responsible for a child she did not want, or that she knew she couldn't afford or because she knew that her life was not conducive for a child.
I am not even going to mention the effect it will have on her life in terms of work, or the frequent doctor visits or getting injected with huge needles the size of a turkey baster for amniocentesis or other things, because that is a given..
This is the primary reason why a woman should always have the right to choose because it is her body and her life that will be the affected the most by it.