We have one. We were in Japan and my wife said, "Oh *****, I forgot to bring my pills." After a week I couldn't take it anymore and said, "Hell, might as well start trying to have kids anyway." We have so many friends that are struggling to get pregnant that I figured we'd be safe for a few months. And one of my teachers in Japan has such a charming little daughter that I figured not all kids are evil, so why not give it a go?
Truth to tell, I shot my wife down with the first salvo...we got back to the USA a few weeks later and she was already barfing from morning sickness.
But we've only got our son...maybe we'll "try" for another in a few years.