How do you know when it's right?

I am new here, and would like a little advice. How do you know when it is right in the relationship to start trying to conceive? Is there a right amount of time to be with someone, or a certain amount of money you should be making? I hear so many different things, and me being 24, i have baby fever a lot, and would just really like to get some opinions from others. I also am concerned that i may not be able to get pregnant, since i never have been and ive been off birth control for three years and there is a history of problems with the female reproductive systems in my family, although everyone that had had problems still had children. Anything helpful, i would greatly appreciate. Thanks.