Robin Roberts and Amy Robach on "Good Morning America" (Nov. 11, 2013)

Robin Roberts and Amy Robach on “Good Morning America” (Nov. 11, 2013)

*ABC News’s Amy Robach reluctantly got her very first mammogram on ABC’s “Good Morning America” last month (in a special “mammo-van” parked outside of the studio) — but only after breast cancer survivor Robin Roberts and a “GMA” producer prodded her to do it.

This morning, it was revealed that her Oct. 1 on-air mammogram resulted in a cancer diagnosis.

“The whole reason I walked into that mammo-van was to raise awareness, for people to get mammograms,” Robach, 40, said on “GMA” this morning, with co-host Roberts and ABC News senior medical contributor Dr. Jennifer Ashton by her side. “And little did I know that I would be a walking example of – having a mammogram saved my life.”

Turning to Roberts, Robach said: “Having you, who pushed me to do this, to say, ‘You can do this,’ you saved my life. ABC News saved my life.” [Scroll down to watch.]

Robach said she was always reluctant to have a mammogram, believing there was no possible way she could have it. She thanked Robin and ABC News “for pushing me into that mammo-van.”

“Because I know me. I wasn’t in any rush to have that done any time soon. And I had cancer the whole time we were sitting in that office,” she said. “I was saying, ‘I don’t have a connection to the disease. Should I be the one to do this?’ And wow. Boy.”

In a post on ABC.com, Robach wrote: “On Thursday, Nov. 14, I will go into surgery where my doctors will perform a bilateral mastectomy followed by reconstructive surgery. Only then will I know more about what that fight will fully entail, but I am mentally and physically as prepared as anyone can be in this situation,”Robach said online. “And while everyone who gets cancer is clearly unlucky, I got lucky by catching it early, and there are so many people to thank for making sure I did. Every producer, every person who urged me to do this, changed my trajectory.”

The thinking behind on-air checkups is to calm fears of millions about the tests; Katie Couric’s colonoscopy on “Today” was credited with a substantial spike in the number of people getting colonoscopies. Last week, “Today’s” Matt Lauer and Al Roker got prostate exams on the air. But today’s news is uncharted territory, Robach’s on-air exam turning up positive.

Watch today’s “GMA” segment with Robin Roberts and Amy Robach below.