But can you imagine it happening twice?
The documentary follows true stories of women who didn't know they were pregnant.
These women experienced no weight gain, no symptoms and no cravings. Nothing.
"How that happened once, let alone twice is so crazy," says Crystal, one of the two mothers on the show.
Crystal loves keeping fit and says she was on birth control both times she became pregnant, so was incredibly shocked when she started having contractions.
Crystal did have intense pains during her first pregnancy, but she put this down to kidney stones.
Once she got to the hospital, it became clear that the pain was actually labour and she was about to give birth.
The same thing happened again just one year later, but this time she unexpectedly gave birth in the bathroom. Luckily her boyfriend and aunt were there to be on hand.
Tawanda's story is slightly different - she was surprised by her first pregnancy after a night out with her friends. She called a taxi to take her home and later realised her waters broke in the taxi.
"I had no clue of even being pregnant," she explains.
In the taxi, she soon realised that a baby was on its way and it was too late to go to the hospital - it happened right there and then.
But 13 years later at a friend's barbecue party, the same thing happened. "This can not be happening again," she is caught saying in the trailer.
Tawanda had four expectedbabies in between, so it was a complete shock for the same thing to happen again, over a decade later.