It turned out to be a false alarm. But Winfrey is now talking about what got her through the agonizing wait that so many women have experienced.
Winfrey shared her story during an event in New York called "O University," a self-help conference. Winfrey said she had just finished visiting with military families when she was headed home to California, but she decided to go home to Chicago and check it out.
"Earlier that morning...I felt a lump in my breast," Winfrey said.
Winfrey said she hadn't shared this information with anyone, including her best friend Gayle King, who seemed visibly upset when she learned along with 5,000 other attendees.
The media mogul said it was her favorite Bible passage that sustained her until she got the results.
"Let me just say, everything is fine," Winfrey said.
It's been a busy week for Winfrey, who has been experiencing some challenges with her cable network OWN.
But the network is emerging with the addition of new programming, something she discussed Monday with late night talk show host David Letterman while at Ball State in Indiana.
Winfrey explained how adversity has been her greatest teacher:
"Had I not had the pressure-- and that's why I'm so grateful for my many years in poverty, because it makes the experience of creating success and building success that more rewarding for me," said Winfrey.
The former queen of talk did not discuss the cancer scare with Letterman, but she did talk about her school in Africa for girls. The philanthropist recently celebrated the first graduating class and says it reminded her of her childhood.
While things are looking up at OWN, reports indicate that sales are down at O magazine. Oprah has hinted she may stop publishing the magazine if it starts to lose money.
Winfrey said she hopes her cancer scare was a wake-up call and raises awareness.
