Serena Williams, one of the greatest tennis players of all time, revealed on Wednesday that she's pregnant with her first child. The 35-year-old shared a swimsuit selfie on her Snapchat featuring her baby bump along with the caption "20 weeks." In late December it was revealed that Williams was engaged to Reddit co-founder Alexis Ohanian. Over the weekend Williams gave a hint that she might be pregnant when she posted another selfie on her Instagram with the caption: "Fighting to get up this morning."