The `Cry Me a River` singer - who is expecting his first child with wife Luisana Lopilato - admitted he "accepted" the fact the couple may have to adopt before his wife became pregnant.
He said: "I was so happy [when she got pregnant]. I honestly thought that we`d have to try for a year or longer. I`d even accepted that not every couple can have a baby naturally and maybe we`d adopt, and that would be okay with me too.
"I just wanted to have a family, to be a dad and to try and recreate what I had growing up for a son or daughter. So it was amazing, a really beautiful surprise."
The 37-year-old father-to-be, who has been married to Luisana, 25, for two years, also said he finds his wife even sexier now she is pregnant.
He told OK magazine: "She`s having a great pregnancy. She doesn`t have morning sickness, she`s very lucky. I find it very sexy, actually. The more pregnant she gets, the sexier she gets. She loves it too. Yesterday was the first day she ever felt him kick. She was really excited about it."