When Serena Williams hinted last week, via a hastily deleted social media post, that she was 20 weeks pregnant, many did some quick math and realized, in that case, she must have been carrying her child when she won the Australian Open in January. On Tuesday, Williams said that she first learned of her pregnancy two days before that tournament began and admitted she was “nervous” about playing in it.

Williams, 35, also confirmed that the Snapchat post in which she leaked her pregnancy was accidentally put online for all her followers to see. “You know how social media is, you press the wrong button and …” Williams said with a smile to CBS’s Gayle King during a TED Talk interview in Vancouver.

Of playing in the Australian Open while pregnant, Williams said, “I was nervous. I wasn’t quite sure what to think, but I knew that at that moment, it was really important for me to just focus.”

“It wasn’t very easy,” Williams, who defeated her older sister Venus in that final, added. “You hear all these stories about people when they’re pregnant — they get sick, they get really tired, really stressed out. … I had to really take all that energy and put it in a paper bag, so to say, and throw it away.

“I really felt that I didn’t have time to deal with any extra emotions, any extra anything, because, pregnant or not, no one knew, and I was supposed to win that tournament as I am every tournament that I show up [for]. If I don’t win, it’s actually much bigger news.”

Williams said her inadvertent Snapchat post occurred while she was “on vacation, just taking some time” for herself. “I have this thing where I’ve been checking my status and taking pictures every week to see how far along I’m going,” she said, adding, “I was just saving them [for myself]. I’ve been so good about it, but this was the one time it slipped.”

In the immediate aftermath of her revelation, Williams said, “My phone doesn’t ring that much, and thirty minutes later, I’d missed four calls. So I picked it up and realized, ‘Oh no.’” She claimed that she was only going to wait  “like five or six more days” before announcing her pregnancy, so ultimately, “it was a good moment.”

Williams’s official announcement came Monday, again via social media, when she posted a love letter to her unborn child, one in which she also celebrated a return to the No. 1 ranking, this despite not having played since winning in Australia for her 23rd Grand Slam singles title, a record in the Open era. She also gave a shout-out to her fiance, Internet entrepreneur Alexis Ohanian, who responded with his own post.

Williams will take the rest of the season off to attend to her pregnancy, but she intends to return to competition next year, even though she will be 36, which is more or less ancient for a tennis player. “I’m not done yet,” Williams told King. “My story isn’t over.”

“I’m really inspired by my sister, who’s a year older than me. If she’s still playing, then I know I can play,” Williams said. “This is just a new part of my life. My baby is going to be in the stands, hopefully cheering for me and not crying too much.”

Asked about her engagement to Ohanian, which occurred in December, Williams said, “When he proposed, I was almost angry. Not almost, I was angry, because it was right in the middle of my training season and I thought, ‘I have to win the Australian Open.’ … I really wanted to pass Steffi Graf’s record [of 22 Grand Slam titles].”

“I never felt pressure to get married, and I can’t say I’m the marrying type. I love my life. I love my freedom,” Williams said. “I hear that kind of changes. I love my career, and I didn’t want anything to interfere with that.”

When King asked how Williams knew Ohanian was “the one,” she laughingly replied that she wasn’t “going to say that [out loud].” Williams did say of her 34-year-old fiance, “He’s very loving and he’s very kind. He’s very considerate.”