Kelly Clarkson reveals on Twitter she's expecting a baby girl

Kelly Clarkson performs on stage at the 55th annual Grammy Awards in Los Angeles on Sunday, Feb. 10, 2013. (John Shearer / Invision)

The 'Since U Been Gone' singer confirmed she is having a daughter with husband Brandon Blackstock Monday morning.

She wrote on Twitter: "We just found out we're having a girl officially! I knew it! Only a girl could cause this much drama with all this vomiting ha! (sic)"

Kelly, who is four months pregnant, has previously tweeted about her battles with morning sickness, writing: "Ladies if your pregnant & sick as a dog trust me when I say the one thing u will keep down might just be "baked potatoes" #godblesspotatoes (sic)"

She also wrote alongside a picture of her dogs: "Didn't throw up once from pregnancy while walking my dogs #smallvictory #TMI (sic)"

Kelly, 31, has also previously said she hopes her baby is "chunky" because she thinks it is cute.

She said: "I want chunky babies. I just love chunky babies. I want to bite their chunky arms and thighs. They're just so cute!"

Kelly and Brandon - who also has children Savannah, 12, and Seth, seven, from a previous relationship - have got some names in mind for their young one, but won't say whether they will be traditional or modern.