Carrie, who won the fourth series of American Idol in 2005, is expecting a baby with her husband Mike Fisher and revealed the news on Twitter.
The country and western singer, 31, posted a sweet photo of herself holding her two pet dogs who were wearing 'big brother' and 'big sister' T-shirts.
Captioning the snap, Carrie said: "In honour of 'Labour' Day...Ace & Penny would like to make an announcement. Their parents couldn't be happier!"
Carrie and NHL player Mike married in 2010 after meeting at one of her concerts in the US two years previously. The tied the knot in front of 250 guests at the The Ritz-Carlton Lodge in Georgia.
Speaking afterwards, the couple released a statement to America's People magazine, saying: "We could not feel more blessed to have found each other and to have shared this day with our friends and family that mean so much to us."
The newlyweds signed the statement 'Mr and Mrs Fisher'.
Celebrities who have announced pregnancies in 2014:
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