Serena Williams is back on the tennis court after welcoming daughter Alexis Olympia in September — but learning that she was pregnant caused her to worry about her athletic career.
The 36-year-old tennis star shared a trailer on Instagram Monday of the upcoming HBO documentary series Being Serena, which follows her throughout the pregnancy and first months as a new mom.
“When I realized that I was pregnant, I was like, ‘Oh my God. How am I going to play?’” Williams is heard saying the clip.
Despite the immense changes in her life, including welcoming the baby and marrying Reddit co-founder Alexis Ohanian in November 2017, the 23-time Grand Slam champion makes it clear that she’s not done with the sport.
“I don’t know if there’s anything left for me in tennis,” she says. “But I’m not done yet.”
Williams captioned the new trailer, “I can’t wait to share what I have been through the past year with you all. My whole life has completely changed.”
RELATED: Prepare to ‘Aww’: Inside the Cuddly Life of Serena Williams’ Daughter, Alexis Olympia
Williams also shared an adorable mother-daughter selfie on Monday, which features the pair giving big smiles to the camera. Olympia dons a headband with a pink flower while her mom goes makeup-free.
The tennis star shared in an essay for CNN that she is “lucky to have survived” following a series of complications that occurred in the days after giving birth. After delivering Alexis via an emergency cesarean section, Williams experienced a pulmonary embolism, the coughing from which caused her c-section wound to open. Doctors found a large hematoma in her abdomen during surgery, and she was placed on bed rest for six weeks.
Want all the latest pregnancy and birth announcements, plus celebrity mom blogs? Click here to get those and more in the PEOPLE Babies newsletter.
RELATED VIDEO: Serena Williams Will Return to Competitive Tennis 5 Months After Giving Birth to Daughter
But despite the health issues, Williams returned to the Women’s Tennis Association Tour earlier this month with the support of her little girl.
“She’s got her Wilson racket,” the athlete said in an Instagram live session, showing off the pint-sized equipment as Olympia kicks around excitedly.
“Honey, are you supporting Mommy?” she asks her daughter, who’s sporting a gold pin in the shape of an “S” on her outfit. “She said today she’s supporting her mama because I’m coming back!”
Although she fell to 20-year-old Naomi Osaka in her fourth match, Williams wasn’t giving up. After the match, she posted an optimistic message on Instagram, writing, “4 months ago I could not walk to my mailbox… but I will keep going forward and I’ll get there.”
Being Serena premieres May 2 at 10 p.m. ET on HBO.