Jen Champney says it was her toddler who first noticed the lump that changed her life.
"He would come up and poke it and kind of look, like questions, like what is that? That really made me pay attention to it," said Champney.
A visit to the dermatologist revealed the bump on her thigh was actually a rare sarcoma.
Champney, who worked for years as an oncology nurse treating cancer patients, was terrified.
"I just couldn’t help think of all the worst case scenarios," said Champney.
And as she prepared for surgery, she and her husband learned she was pregnant.
"I was crying hysterically and he said are you happy? And I said I don’t know, because I was so afraid," said Champney.
But Jen and her unborn son survived the surgery at Brigham & Women's in September - with a little help.
"On my difficult days when I was feeling particularly emotional and afraid and crying, I found strength remembering my former patient and all of my patients," said Champney.
One of those patients was Jennifer Goodman Linn, who founded Cycle for Survival - a fundraiser for rare cancer research. This weekend, when survivors and family members hop on bikes at Cycle for Survival in Boston, Champney will be among them.
"It was something that I had to do," said Champney.
And some day she'll explain to her son how he helped save her life, too.