FEMINISM - Motherhood isn't for everyone. Its not really a feminist issue. Its just a matter of choice. (Its the ability to have a choice [or a vote] is where feminism comes in.)
Some women don't hate children, but they don't want them either. That's why some women decide to get her tubes tied. They KNOW, for whatever reason, that they are just not the mothering type. This is a difficult concept for some people, including myself who adores kids (and have dedicated my life to teaching them) but eventually I came to the realization that this was HER CHOICE. She had made the decision she didn't want kids, and even if she changed her mind later she could always adopt. Arriving at this decision can be difficult, but once the decision is made "getting fixed" is the easy part.
There are a variety of techniques for those sexually active women out there who want to neuter themselves. If you're curious about them I suggest researching the different techniques, their benefits, whether they can be reversed, possible side effects and of course talk to your doctor (who will ask you a series of questions to check your seriousness, like "What if you met a billionaire who wanted to have kids with you?").
Telling your parents might be the most difficult part. They have a tendency to cry when they realize they will never have grandkids.
(NOTE: According to a male friend some guys also think about getting fixed too, and he even discussed the matter with his parents and they were vehemently opposed to it. He has yet to do it, but he was seriously considering it apparently because he believes strongly in adoption.)
So when you think about it choosing not to have kids is not really a feminist decision. It doesn't make you a heartless bitch either. Some women just don't feel like being mothers. Some want to get married and have kids. Some even prefer to be single parents.
Feminist Perspectives on Reproduction and the Family
Wombs for Rent
A Woman's Choice - Abortion and the Right to Choose