I want kids in about 8 years and so does my wife, so it would be a bummer. Secretly, I would be kind of relieved as I wouldn't be spreading my shitty genes around and could adopt kids and make a difference.
I'd feel horrible, especially for my girlfriend. We both want kids in a handful of years, when we'll buy that house we want. It would probably disappoint us, but we'd very likely end up adopting a child.