Singer Kelly Clarkson was forced to announce her pregnancy early after a bout morning sickness prompted her to cancel a promotional appearance.

The Since U Been Gone hitmaker was hoping to keep the happy news to herself until closer to Christmas (13), but she was too ill to hide the secret.

She tells U.S. breakfast show Today, "I don't know why they call it morning sickness because it's like all day and all night.

"I was just dying to tell people, but we were trying to wait until the end of my first trimester... but everybody kept talking about it and I had to cancel something because I've been so ill. I didn't want people to think that I'm cancelling because I'm lazy or something. So, we just told people. But we had a really good reason."

Clarkson, who wed Brandon Blackstock last month (Oct13), announced she was expecting her first child earlier this month (Nov13), and although it is too early to tell, she is convinced she is having a girl.

The 31 year old already has a name picked out, but refuses to reveal it.

She continues, "We're not saying because I don't want someone to steal my baby's name."