She tells People magazine, "It was natural. We didn't do in vitro, which I know was reported. Everybody assumed that because we had twins. I wanted to have a baby, but I've always said exactly what I said all those years they (reporters) asked us since we've been married: 'Well, when are you guys gonna have some kids?' 'When it happens naturally, I guess!' And that's when it happened. It was a surprise to us."
Lopez, 38, admits she often doubted whether she'd ever become a first-time mom.
She adds, "You start getting older, you think to yourself, 'Maybe (having kids) is just not meant for me.' I knew there was nothing wrong with me. I knew that I could. Deep down, I really wanted it badly... (But) after one year, two years, three years... You know, you start thinking to yourself, 'Well, maybe...'"