I would carefully think this through. You've gotten some good answers already about the technical aspects of FMLA, however I'd like to emphasize that you should carefully consider this from a career management point of view. You don't say what type of work you do, or how committed you are to your job/career. If you work a job that, to you, is "just a job", then this may not matter to you so much.
But if you have a job that you would want to continue with and a build your career from, then you might want to give this more thought. To the recuiter's point (who responded below), a company makes a big investment when they hire someone (cost of hiring, training, etc.). They have a business need to have your position filled with the most capable person possible, and chances are it also costs them (ie; opportunity costs, temp hiring, stressing their staff who has to fill in) to not have someone working in the position -- especially now when most companies are so lean.
Obviously, life has a way of throwing 'curveballs' sometimes (and no employer can/should EVER tell you when to begin your family), but if you go into your new job with the expectation that you'll be taking a substantial amount of leave within a year and racking up all kinds of medical/disability benefits, you could jeopardize your professional reputation to a certain extent. Granted, as someone said, if you got sick, it would be a non-issue. But if word got out about your intentions (or people surmised it on their own), you might be seen as not very reliable and just using the company (remember, you might want your most recent employer as a reference if you look for work again someday).
If your career matters to you, I would wait at least a year before trying and put every ounce of effort into doing such a good job that you'll be sorely missed during your leave - regardless of whether you intend to come back. If it doesn't, (or if there are other siginificant factors as to why you must start a family immediately) then these points are moot and I wish you all the best.