It is not a sin to not want to have kids or say you don't like kids. It really gets me mad when people think this way, or have the nerve to comment on the state of someone's childlessness. Why do people think all women want kids or are enamored of the whole motherhood thing?
My kids were very wanted and planned, but there was a time when my DH was extremely close to having himself fixed, because I decided I didn't want kids. I was going to be a professor... until one day I stood in the ASU bookstore and got totally obsessed by the books about pregancy and babies. I never could have predicted it. I had excellent parents, so it wasn't that; I just knew I was not willing to give up my whole life. And, I didn't. Believe me, I heard about that. I fully admit to liking my own kids more and more as they grew up. Babies and toddlers, well, that was a stage to get through, until the real fun began.
In retrospect, I did what was best for me, as far as both my mental and physical health went. I married someone who is an excellent parent, despite coming from an abusive home. We were young and had the energy, so it worked out. I think, though, my younger son might say I was a little selfish, but he was a difficult kid when he was young. I often think having one kid might have been a better choice for me, but he was the one that kept us laughing. And now, people are asking me if I want to be a grandmother!! Jeez, it never stops. I quite emphatically say no to that, because at this point, I really do not care.
And besides, how can you be a grandmother when you still feel like a kid?