Monica Thompson had given up on her dream of having children after 16 years of trying to conceive with her late husband. So when the 46-year-old discovered she was pregnant - and not just pregnant but ready to give birth - the news came as a shock.
Speaking to Inside Edition, Ms Thompson shared that she was at work when she began having stomach cramps. Thinking she had the flu, she took herself to emergency,
"The doctor comes in and he asks, 'Do you think you might be pregnant?' I'm like, 'Haha, yeah right. There's no way. I'm too old to have children. I am probably going through menopause,'" she said.
A pregnancy test confirmed the doctor's suspicions - Ms Thompson was seven-and-a-half months along.
"You are having a baby now," she was told.
Ms Thompson's fiance, Jason, was also shocked. "Is this a joke?" he asked. " Are you kidding with me? What's going on?"
Just 24 hours after learning they would be parents, Ms Thompson underwent an emergency C-section. Little Jayden weighed just 3 pounds, 9 ounces and was admitted to neonatal intensive care.
He's now a happy and healthy eleven month old.
In an interview with The Sun, Ms Thompson said that the surprise meant she felt a little "robbed" of her pregnancy. " I never felt my baby move and I never got to have that ultrasound moment where I saw his heart beat."
But she's thrilled to be a first-time mum at 46.
"I think it's extra special to become a mum at this age," she said. "Of course I would like to have been younger, but I know more now.
"I just feel very grateful that I have the chance to be a mom when I had given up on that dream."
While so-called "cryptic" or "denied" pregnancies might seem rare, they're not nearly as uncommon as you'd think.
In an article for The Conversation, Helen Cheyne, Professor of Midwifery Research, notes that these pregnancies occur in around one in 2,500 cases,
"Various physiological or psychological theories have been suggested to explain cryptic pregnancy," she writes. "While it may occur more commonly in women who have a co-existing mental health condition, many cases occur in women who have no evidence of underlying mental health problems and its cause remains unknown."
And their impact is not to be underestimated.
"For all women, pregnancy is a time of change and preparation for motherhood. While the reality of motherhood may still surprise any woman, those who are unaware of their pregnancy are likely to be profoundly shocked by their unexpected motherhood. This can be extremely difficult to overcome."
That's the situation 22-year-old Melbourne student Kate Hudson faced when she discovered she was 33-weeks pregnant during a European holiday in 2014.
I had absolutely no real clear symptoms," Kate told The Young Mummy blog at the time.
"I was still getting regular periods, I wasn't nauseous, no morning sickness, little weight gain … it seemed silly to think I was pregnant.
"All I had leading up to it was a little constipation and I went from a C-cup to a D-cup."
Upon her return to Australia, however, the mum was told her baby was overdue - and needed to be induced.
"I was scared about the future," she said. "Being a mum is daunting. I had no money since I had just come back from overseas. Where will we live? How will we pay for stuff? I didn't know all too much about babies."
Doctors explained that young mum's uterus was tilted back and her baby had been sitting up high in her diaphragm, concealing his presence.
A 2016 study published in the Journal of Emergency Nursing highlights other potential contributing factors including: "inaccuracy of home pregnancy tests; weight gain that is not noticed in overweight women; minimal pregnancy symptoms; an irregular menstrual cycle; a fetus that moves minimally in the womb; infertility diagnosis; stress and denial; and psychiatric conditions such as bipolar disorder or schizophrenia."