Women not wanting children is no more unnatural than men not wanting them. The purpose of all life is to reproduce and create more life, ensure the survival of the species, but at the same time I think it's safe to say a) we've evolved enough to think beyond those base biological impulses and b) the population of the world isn't solely in our hands (or ovaries). Society is still relatively outdated in that it tends to put pressure on women who don't want children, but you should never be made to think that you are weird or unnatural or cold for not wanting them. Some people just don't. And if you don't, it's far better for everyone that you stay true to that. Don't let anyone make you feel guilty for being happy without them.