Serena Williams revealed on Snapchat today that she's 20 weeks pregnant with her first child. The 35-year-old tennis great posted a selfie that shows her wearing a yellow one-piece bathing suit with a cute baby bump, captioning the snap "20 weeks." On Tuesday, Williams shared a playful pic that shows her 33-year-old fiancé Alexis Ohanian lifting her up in his arms while the two were on a beach, but there was no hint of a baby bump visible in that image. Williams and Ohanian got engaged in December, while in January she claimed her 23rd Grand Slam title by winning the Australian Open--apparently while pregnant! More here.