In an interview to The Mirror, the 43-year-old star said she couldn't be more delighted.
"We hadn't been trying. But he was over the moon and so was I. I think we'll be good parents together. He's got a lot of time and patience. I just think this will complete us. It's the happiest I've ever been.
"He is a hundred, million per cent the reason for my current happiness. I've been lost a lot in my life. Now I'm centred," she said.