Kelly Rowland admits her pregnancy wasn't planned.

The 'Motivation' hitmaker, who is expecting a baby boy with husband Tim Witherspoon, was initially shocked to discover the news, but has already chosen a name for their son.

The 33-year-old star said: ''It was a surprise, I can definitely tell you that. It was a great surprise!''

She added: ''The dad picked out the name. It has to do with family.''

Kelly is really enjoying her pregnancy, but is struggling to adjust to her new curves.

She said: ''I had no morning sickness. I feel great.

''The most shocking thing about pregnancy to me is probably the way your body changes -- nobody can prepare you for that. Not a book, not anything. You just go through it.''

The former Destiny's Child star has been sticking to a healthy diet, but is giving in to some of her cravings.

She told PEOPLE.com: ''I love sandwiches right now. I'm reading these different books and they're telling me what food is really great for the baby, to grow their nervous system, and their brain food and all that, so I've been trying to stay on that.''

Asked what she's most looking forward to about motherhood, she said: ''When I see the baby's face. That's it.''