Jessica Simpson: 'I'm Still Pregnant'

04/21/2012 at 01:15 PM EDT

Jessica Simpson is still expecting.

The mom-to-be, who celebrated her "dream" baby shower in March, is setting the record straight about the arrival of her first child.

"To everyone who keeps congratulating me on the birth of my baby girl," she Tweeted Saturday, "I'm still pregnant!! Don't believe what you read ladies and gents."

Simpson recently played bridesmaid at a pal's wedding, which she attended with fiancé Eric Johnson.

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"Jessica looked stunning," a source told PEOPLE of the event. "She was moving very slowly and Eric held on to her tightly so she wouldn't trip in her shoes."

(The star, 31, has said she's "waddling" but still wearing high heels.)

Added an eyewitness at her friend's nuptials, "It was difficult for her to get around, but she was a great sport and kept smiling."

And she's kept her sense of humor.

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