Phoebe Quatre-Morgan went to her doctor with her mum, complaining of a swollen stomach.
The doctor was so convinced she was expecting a baby that he told Phoebe's mum, Ramona, her daughter was hiding the truth.
But Phoebe, from Bolton, Lancs, knew for a fact that she couldn't be pregnant and when she had an ultrasound scan her protests were confirmed.
Instead, though, she was given the shattering news that she had an ovarian tumour – and will now never be able to have her own children.
I knew there was no way I was pregnant and to be told that I was, by my GP in front of my mum, was devastating," said Phoebe.
"The doctor was convinced I was, telling my mum that it was common for young girls to hide pregnancy from their families – my mum was just as shocked as me about what the doctor was telling us. I kept telling the GP I wasn't but she just didn't listen.
"When we went for the ultrasound there was obviously no baby but we still didn't know what the massive lump was.
"When I got the diagnosis, I had a mixture of emotions, from relief they had finally found what was wrong but at the same I had just found out I had cancer – at 16 years old."
After the scan revealed the growth, Phoebe had surgery to remove it and was given the all clear in January after chemotherapy. But in April, six weeks after her 17th birthday, she was told the cancer had returned.
She needed a hysterectomy which means she will never be a mum but has been given the all clear for a second time at the Christie Hospital in Manchester.
Phoebe has gone back to college to resume her A-levels.
It's hard being told I'll never have children. But cancer has made me just enjoy life," said Phoebe.
A spokesperson for NHS Bolton said they would investigate the case with the GP's practice.
What a shocking story!