Williams, 35, announced her pregnancy on Snapchat, Wednesday, sharing a photo of herself sporting a baby bump with the caption “20 weeks” – though she quickly deleted the image.
Here’s everything we know about the happy parents-to-be.
While Drake was in the stands at the 2015 U.S. Open to cheer on Williams, so was Ohanian – he shared a photo of the athlete on the court, writing, “Come at the queen, you best not miss. #USOpen.”
Though Ohanian continued to hint at the romance on social media throughout 2016, the tech mogul didn’t pop up on Williams’ account until last fall, when he posed for a group photo among her friends.
Of the image, Williams teased Ohanian as a “nerd.”
For Halloween, Williams posted a photo of herself and Ohanian dressed up in bear-themed costumes.
By the end of the year, the couple was engaged. Williams broke the news with a poem – on Reddit, of course.
“I came home. A little late. Someone had a bag packed for me. And a carriage waited. Destination: Rome,” Williams wrote on her Reddit account.
“To escort me to my very own ‘charming.’ Back to where our stars first collided. And now it was full circle. At the same table we first met by chance,” she wrote. “But by choice. Down on knee. He said 4 words. And I said yes.”
At the time, a source told E! News that Williams friends had “never seen Serena this happy before with a man. It sounds cheesy, but it was love at first sight.”
“They laugh non-stop and that really fuels their relationship,” the source added. “They are on the same page in life and are excited to start something great with each other.”
Responding to the exciting news on Twitter, Ohanian wrote to fans, “Thank you all for the kind words. Especially from all my Armenian brothers and sisters debating when they can claim Serena as Armenian.”
In early January, Williams headed down under for the Australian Open, and showed off her engagement ring for the first time.
Opening up about the engagement in a post-match press conference after securing a first-round victory in the Open, Williams told reporters, “It feels good.”
“I really haven’t thought about it too much, because I wasn’t even really gonna think about it until after the tournament,” Williams continued. “So, I just keep saying, ‘February, I’ll start looking at the bigger picture of my life.’ But right now I’m just so focused that this is all I can think about.”
She added of Ohanian, “He’s incredible — a really nice person. I think he definitely treats everyone the same, which is really cool to see. Really, really nice to see.”
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During a later match in the tournament, Williams was caught blowing a kiss to Ohanian, who was watching from the stands.
Williams went on to best sister Venus Williams in the tournament – while about 8 weeks pregnant, as we now know.
Still, there’s no hard feelings between the pair: in fact, Venus previously told PEOPLE that she’s “so excited” for her sister’s nuptials.
Said the athlete, “She is so prolific on the court, but now I am happy to watch her prepare for her wedding!”