In the early hours of a Sunday morning last autumn, the week before her 18th birthday, Beth told her dad that she was in “absolute agony”. She’d been having stomach cramps so intense that she collapsed in college on Wednesday, but she put the constant need to go to the toilet down to IBS. She’d taken pregnancy tests weeks before; the result was always negative, and she hadn’t had sex since, so when they called 111 and the nurse asked if she was pregnant she said no. But hours later, Beth was taken to A&E where she gave birth to a full-term baby: a 7lbs 5oz girl, later named Maizie.

She showed me pictures from her last holiday in August. She’s visibly slim – eight stone, she tells me – with a flat stomach, and no sign that she would have been seven months pregnant at the time. At this point in a pregnancy, most people would have a prominent bump, and would’ve been able to feel their now cabbage-sized baby moving around for the previous two months or so. But Beth didn’t.

In the months leading up to Maizie’s delivery, Beth had just been doing typical teenager stuff: getting bored of her hometown, St-Anne’s-on-the-Sea, studying, seeing a guy from college, who she was starting to go off anyway, working shifts at her local Wetherspoons, doing army riot training, and drinking at Blackpool Pleasure Beach with her friends.

There are multiple reasons for the occurrence of a cryptic pregnancy, which include: having two wombs so the baby forms in the one closest to the spine and no bump is formed, having a tilted cervix, or producing low levels of hCG (the hormone produced by pregnant women and picked up by home pregnancy tests). These problems can fly under the radar because there's no way someone would know how many wombs they have, most people do not undergo routine ultrasounds, and you’d only check your hCG levels once you knew you were pregnant.

She had a cryptic pregnancy – one that goes undetected by home pregnancy tests, produces no bump and comes with minimal symptoms (and those symptoms can easily be mistaken for other conditions anyway). Recent figures say these happen in approximately one in 475 pregnancies . Some women with cryptic pregnancies find out seven or eight months in, but there are many women who, like Beth, find out that they’re pregnant literally as they start giving birth.

Every so often a new cryptic pregnancy story appears in the media. See “ Oldham teenager in coma wakes up with 'surprise' baby ” or “ Woman, 22, who only realised she was pregnant when she gave BIRTH ”. These stories are shocking and, in the latter case, greeted with judgment, and they do little to explain the experience of a cryptic pregnancy and what happens to these women afterwards. So I traced the stories of three mothers – Beth, Klara and Lily – to find out what happens when you give birth unexpectedly. How do you come to terms with 'surprise' motherhood? How do you deal with the judgement that comes from it?

For Klara, who had a cryptic pregnancy in 2016 when she was 22, the fear that enveloped her was that she was having a miscarriage. “In my head I’m thinking, maybe this is a miscarriage?” she says. “But if it was a miscarriage then I’d be nine months pregnant by now because that’s the last time I had slept with someone.” She remembers how her neighbour came to help her when she heard her screaming – “I told her I was having a miscarriage, and I needed an ambulance to come.”

“We went to A&E because I had started bleeding and [the nurse] was like, ‘Well I think you’re pregnant and about to have a baby,’” says Beth, while bouncing a now six-month-old Maizie on her knee. “So I was given a huge tank of gas and air and rushed to delivery. Turns out I was 9cm dilated and you have to be 10cm to start pushing. So around two hours later, she was out.” Did she feel scared? “I wasn’t really thinking of much at the time,” she says. “I was more bothered about getting out of pain, to be fair.”

Klara had woken up on the morning of her first day at a new job with “terrible period-like cramps”, and her mum encouraged her to take painkillers and continue her day as usual. The pain became too intense and she left work early, arriving home just hours before she gave birth to her daughter, Amelia – now three years old – while on the toilet. “I was sitting on it and my body just lifted itself,” Klara tells me, getting off the sofa and squatting to demonstrate. “My cervix tilted forward and I caught Amelia, just before she fell into the toilet,” she says holding her hands between her legs.

“I had four paramedics peering into my tiny bathroom,” she continues. “Luckily, one of them was a lovely mumsy type and she just held me while I cried and cried and cried. It’s all such a massive blur. I don’t know if I’ve repressed it, it’s just such a stressful point, realising that everything is about to change. All I was thinking was, ‘I need someone to help me clean the toilet because what if my mum comes home and finds this bloodbath in the bathroom?’ So one of the paramedics gave it a little swirl.”

Often when these stories arise, most people ask how it’s possible to not realise. “I walk around the house naked sometimes and there was nothing for mum to say I was pregnant, so she was the most shocked," says Beth. Klara’s body didn’t change much throughout her pregnancy either. “I was a stone slimmer than I am now,” she says. And periods were no indicator for her, as she'd been on the combination Pill for around six months. “I hadn’t had a period for about five of those months. I did have slight spotting, but it wasn’t like a full-blown period, so in my head I was like, ‘This is a period, so it’s fine.’”