Serena Williams on her decision to stop breastfeeding

Serena Williams is opening up about motherhood.

The tennis star -- who won her first Wimbledon match of the year on Monday, just a month after withdrawing from the French Open due to a chest muscle injury -- spoke about her decision to stop breastfeeding her daughter Olympia, whom she shares with husband Alexis Ohanian, co-founder of Reddit, at a news conference in London on Sunday.

"I feel like everyone says, 'You're so thin when you breastfeed,'" she explained at the conference, according to Today. "What I've learned through the experience: everybody is different, every person is different, every physical body is different. For my body, it didn't work, no matter how much I worked out, no matter how much I did, it didn't work for me."

Along with her regular workouts and vegan diet, once she stopping breastfeeding the now 10-month-old, Williams immediately started dropping weight, losing 10 pounds in just a week.

"It was crazy. I just kept dropping. That's when I learned that everything was different," the 36-year-old said. "Sorry to go on about that, but I wanted to say that so women out there know that's not true. Everyone takes things different. I think it’s important for us to share that message."

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Berries and beets 💋

A post shared by Serena Williams (@serenawilliams) on Jun 13, 2018 at 9:44am PDT

Williams, who gave birth in September, said she originally planned to stop breastfeeding Olympia in January, but kept extending the end date.

“Then January became March. March became April. I was still breastfeeding," she said. "For me, it was really important to make it through three months, then it was important to make it to four months. I was like, 'OK, I can do six months.'"

Though she's ultimately happy with her decision to stop, it definitely wasn't an easy one to make.

"I literally sat Olympia in my arms, I talked to her, we prayed about it," she said. "I told her, ‘Look, I’m going to stop. Mommy has to do this.’ I cried a little bit, not as much as I thought I was. She was fine."

ET caught up with Williams in March where she opened up about mom guilt and wanting another baby.

"Working motherhood is real. It's so real," she joked. "But I have my priorities and Olympia is that. And Alexis works all the time as well. He's not even here right now, he's working on his new VC fund. So, that's great! But I'm never a day without Olympia. She's my priority, and every day I need to be home with her. I don't wanna miss any moments with her."

She continued: "I definitely want two [kids], God willing. But right now, I want tennis as well. So, I'm going to wait and see what happens."