Serena Williams tells daughter she is pregnant in emotional video

Serena Williams served a big surprise to her daughter, Olympia, telling her that she will be a big sister!

"It turns out I'm not getting fat, but I have a baby in my belly," Williams says to her daughter in the video.

"You're going to be a big sister," she told Olympia, who at first could not believe the news.

Olympia then began celebrating and running around the room.

Williams can be seen laughing and crying as her daughter jumps around.

Williams retired last September because she wanted to grow her family.