Couples that have decided to not have children.

Ha
My boyfriend and I have come to the decision that we most likely won't want children in the future. I'm 22 and I know that how I think now might be different 10 years from now, but for now I just can't see children in the future. 
Whenever I mention to people that I don't wanna be a mom they all criticize me. It's quite annoying :(
For anyone that hasn't had children.. What influenced your decision? Do you regret it at all? What are some of the pros/cons youve experienced in not having children?