I don't mean to be or sound patronizing here, but you sound very young and I have a feeling you will come to at least somewhat understand sex better when you get older.(ok one more post)
I understand that there are many side affects of having a child. it's very painful too and I'm not saying that a woman is wrong in not wanting to experience that. but at the same time, sex is part of our human reproductive cycle. so if someone really felt strongly about not having a child, they wouldn't have had sex in the first place. killing a child because a mistake you made is wrong. when I make a mistake, I have to live with the consequences. its not like I can just go to the doctor and get rid of the consequence of my mistake, it doesn't work like that in real life. you make a mistake, you own up to it and accept the consequences. in the case of sex, the consequence is often a child. so why is it that women and men who take part in that act shouldn't have to pay for the consequences of their mistake? is the consequence more severe? yes! Very much so! but it was their choice to have sex, so they should be ready to accept everything that comes with that.
the only exception I would ever give is the case of rape. but I would strongly suggest finding an alternate method. like adoption for example.
Sex is more to humans than just a means to procreate, we along with Dolphins have sex because it feels good. To expect adults who don't want to have children to refrain from having sex is beyond unrealistic. And not all unwanted pregnancies are a result of mistakes (and I'm not even talking about rape). All kinds of birth control can fail, even condoms. You can do everything right and still find yourself in that position.
And to say that a woman who terminates a pregnancy escapes without consequences is rather naive. It is a terrible choice to have to make, and many have to jump through so many hoops and face so much condemnation for it. In the US they often have to go past vicious protesters, in Ireland they had to travel out of the country to even have it in the first place (thankfully those archaic laws have been voted down), in some parts of the world they can be jailed for it (there are women who've been jailed for suffering miscarriages), and in other parts where there are no safe options, they could get permanently damaged or die from the procedure - yet some will still seek it (which illustrates how desperate the situation can get).