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Carrie Underwood Nervous About People's Choice | Carrie Underwood
She survived Simon Cowell and American Idol three years ago. She's proved her staying power with two hit albums. Yet being up against Rihanna and Taylor Swift at Wednesday's People's Choice Awards is giving Carrie Underwood the shakes.

"They're both so big, and there's great competition. I'm nervous and so excited at the same time," she tells PEOPLE of being up for favorite female singer and favorite country song.

Underwood, 25, is also hitting the stage to perform her ballad, "I Know You Won't," complete with a full orchestra. "It's a really emotional song about a guy who just won't call. We've all had that happen, right?"

Living up to her fashionista image, the country singer will be donning three different brightly colored gowns at Wednesday's show, to air live on CBS at 9 p.m. ET. "When I was trying things on the neon colors made me happy," she says of her dresses by George Chakra, Zuhair Murad, and Naeem Kahn.

In a special collaboration to mark both PEOPLE Magazine and the People's Choice Awards' 35th birthdays, a special award will be given to the Favorite Star Under 35.

But win or lose, it's all about the fans. "It means so much that the fans are still supporting me and that I had fans before I even had a career," says Underwood. "They've been there with me the whole time."

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