The new mum had none of the usual symptoms – no morning sickness, back pain or sight of a baby bump – and despite not having a period for the nine months she wasn't worried, as she had been on the pill continuously. On the morning of her labour she put painful cramps of the birth down to a heavy period.
Just like any other day she went to work, including a two-hour standing meeting, but had to go home with intense pain. Klara had then managed to lock herself out and had to wait two hours for a locksmith. When she finally got into her house she said the only place she felt comfortable was on the toilet.
'I heard a knock at the door and managed to drag myself off the toilet and open it - by this point I was bleeding heavily,' she told MailOnline.
'My neighbour came in and I asked her to call an ambulance. Then I had this extremely painful urge to push: that's when the head came out. My neighbour was in the corridor and I was screaming: "It's a baby, oh my God! It's a baby."'
Only minutes later Klara was holding her healthy 7lb baby girl, who she named Amelia.
Gaining just 28lbs during her pregnancy Klara said she put the weight gain down to her recent breakup with her baby's father.
'Most women at nine months are huge - my mum gained nearly six stone with me,' she said.
Klara's experience is known as cryptic pregnancy, and actually happens to more women than you might think. One in every 450 British women don't know they're pregnant until week 20 of their pregnancy, which is half way through a full-term. Not realising you're pregnant until the moment of birth happens to one in every 2,500 women. Dr Helen Stokes-Lampard joined Klara on This Morning and said has seen half a dozen cases just like this - before revealing it's happening every week to a woman somewhere in the UK.
Klara spoke about adjusting to life as a new mum, saying, 'I was looking forward to having a normal nine-to-five job, then my life changed overnight, in the blink of an eye, with one long, hard push.'
Has this ever happened to someone you know, or maybe even you? Leave us a comment below!