Serena Williams makes big reveal about her pregnancy

Is Serena Williams planning on finding out the sex of her baby before she gives birth?

The tennis star and fashion designer took to social media on Monday to reveal that no, she isn't going to know her baby's gender in advance. She's going to wait.

SEE ALSO: Serena Williams says she's been playing tennis 'once a week at minimum' during her pregnancy

"So few surprises in life these days, that's why I'm waiting to find out the sex of the baby," she captioned a recent photo of herself. "@SurveyMonkeyrevealed your guesses!"

See photos from Serena's pregnancy:

The reveal comes after month of speculation about whether or not Williams, who serves on the board of Survey Monkey, plans on revealing her baby's gender ahead of time. The comments on her Monday afternoon post reveal that Serena's fans are pretty much equally divided on whether they think she's expecting a boy or a girl.

The 23-time grand slam winner spoke to AOL Entertainment earlier this month about her pregnancy, and revealed that she's taking her time on putting the baby's nursery together.

"[I'm] working on the nursery ever-so-slowly [because] I don't want to get it done and not have anything else to do," she told us of the project. "Each week, I have small goals. That's how I've been spending my time."

But that's not all she's been doing: Williams, who famously told Vanity Fair that she wants to return to the WTA tour as early as January, has also been making sure to stay fit during her pregnancy, and she's been playing tennis "once a week -- at minimum."

"Some days I'll do a long walk and most days I do pool workouts, which are fun and new for me, because I never really do that," she told AOL Entertainment of her pregnancy fitness routine. "It's been really fun and totally different! I try to play tennis once a week -- at minimum -- and sometimes I try to make it out twice a week. I don't do too much. No running or anything like that; I just kind of relax and have fun and work on my stroke. I'll tell my hitter that I don't want to lose my touch, and he just laughs at me."

For more from our interview with Serena Williams, watch the video above.

See more photos of Serena Williams:

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