ABC News' Natasha Singh reports:

Months before former "Dancing with the Stars" co-host and ET correspondent Samantha Harris received a diagnosis of breast cancer, the TV personality had a mammogram and got an "all clear" from her doctor.

The mother-of-two said it was a "gut feeling" that the lump in her breast was something more that led her on a months-long journey of tests and doctors.

Read: Former 'DWTS' Co-Host Samantha Harris to Have Double Mastectomy

"It took me four months to go, 'This doesn't sit right with me,'" Harris, 40, told ABC News' Amy Robach. "Four months later, when I went to see my specialist, I had a needle biopsy, after two ultrasounds, and I had an MRI right before we scheduled a lumpectomy."

"Even the pathology they do in the operating room said no cancer, so I came out and my husband, right next to me, said, 'Babe, you're all clear,'" Harris said. "I didn't even take him to the follow up because I thought I didn't have cancer."

How Former 'DWTS' Co-Host Samantha Harris Decided to Tell Daughters She Has Cancer

Harris was alone in her doctor's office when she received the news that she did, in fact, have breast cancer.

"I started to realize that they kept saying the word 'Carcinoma,'" Harris said. "That means cancer, so I guess I have cancer."

Read: Traveling with the Stars: Samantha Harris

"Then the tears welled up in my eyes and it wasn't until the surgeon left the room that all I wanted to do was crumble into my husband's arms."

Harris said she decided to have a double mastectomy to treat her cancer because it "came down to percentages" and the double mastectomy gave her the "best chance."

Foremost in Harris' mind when making the decision, she says, were her two daughters with husband Michael Hess: Josselyn, 6, and Hillary, 3.

"It puts you in a completely different place when you're a parent and you have a diagnosis like this because you think of all the things you want to make sure you're present for," Harris said. "I lost my dad to colon cancer and he was just 50 and to have him not present when I got married, when I had my first daughter, then my second, has been really hard for me."

"I always think in the back of my mind, 'I don't want to not be there for my kids,'" she said.

Harris says she and Hess together told each of their daughters the news separately so that they could "tailor" what they told them to make it age-appropriate.

Harris said she is now receiving support from the "sisterhood" of breast cancer patients and survivors, including ABC News' own Robach, who is currently battling breast cancer, and Robin Roberts, who has beat both breast cancer and, more recently, myelodysplastic syndrome or MDS, a rare blood disorder.

How Robin Roberts Overcame the Most Tumultuous Year of Her Life

"I have to tell you," Harris said, "reading your story and Robin's gave me so much inspiration and gave me hope that I too will get through this as you are currently doing and as Robin has, and be stronger and a better person on the other side."

"This is a sisterhood that you never want to be a part of but the women I have met through this already are incredible women," Harris said.