Kay Locke, 50, from Stockport, waited 41 years for the diagnosis that would finally allow her to accept herself as she was.
"I used to think there was something socially unacceptable about me," she explained.
"People didn't like me even though I was trying my best to be nice. I'd always irritate them in some way and then I'd never see them again. I did want to be social, I just didn’t know how."
During those four decades Locke found it difficult to maintain friendships, because she struggled to fit into society's expectations of the way a woman should behave and feel.
"I felt the pressure to be - for want of a better expression - ‘normal’," she explained.
"It is different for men. My father was very quirky and people liked the fact that he was awkward, moody and tricky - in my experience that’s more socially acceptable for a man than it is for a woman."
"When I was younger I was probably a bit of a nightmare," Locke recalled. "I'd say things that could seem very inappropriate or thoughtless."
She struggled at school, where teachers labelled her a "dull child" who "couldn't learn" (though she has since gone on to complete many Master's degrees and founded her own business Yoga2Calm), she was badly bullied and often missed lunch as going into the dining room would have meant putting herself into a social situation she didn't know how to cope with.
Locke developed coping strategies so she could "pass" in social situations.
"I try to avoid small talk," she explained. "If someone asks 'How are you?' I'll be thinking that’s a really open question and I don’t know how to reply.
"But I've learned to just say: 'Oh I'm ok. How are you?' That might sound like only a little strategy, but for me knowing what to do in that situation is quite a big deal."
However, although Locke learned to navigate interactions, they didn't become any easier for her.
"When I have to cope in a social situation, I can get a really bad stomach upset and be ill," she explained. "It’s my anxiety getting the better of me. I learned to just accept it as part of my life."
Which is why after years of feeling like there was "something wrong" with her, being diagnosed as being on the autism spectrum came as an "absolute relief".
"Looking back it was obvious," she said.
"I now know that I couldn’t function in the classroom because I was overloaded and that made me very anxious. I was constantly in fight-or-flight mode, but no one ever noticed that, they just labeled me as 'stupid'.
"I had lots of symptoms as a girl and as a young woman that were just ignored.
"In fact it’s laughable, I actually had my tonsils taken out when I was 21, because they thought that would stop me feeling sick. It never ever occurred to anybody that the symptoms I was repeatedly expressing were caused by anxiety."
Locke is not alone, according to Carol Povey, Director of the National Autistic Society’s (NAS) Centre for Autism, many women on the autism spectrum spend years living without a diagnosis.
"We often find women are diagnosed later in life after having been misdiagnosed with eating disorders, bipolar or personality disorders, when clinicians were unable to pick up signs of Asperger syndrome," she explained.
"The NAS Lorna Wing Centre for Autism specialises in diagnoses for women, who often seek diagnoses later on in life after being misdiagnosed - but there is still a long way to go.
There are still thousands of women and girls without the right diagnosis who are looking for support but unsure of where to turn.
Locke may have on some level been expecting her diagnosis, but it came as more of a surprise to many of her friends and acquaintances who didn't believe she had all the traits 'necessary' to have autism. Even now she is often told: "You don't look or act like you have autism".
But as Locke well knows, there is no one way to look or act like you have autism.
Locke and her husband Martin have two daughters, Natasha, 24, and Olivia, 15, who have both been diagnosed as being on the autism spectrum.
Like all children they are very different, and their experiences of autism are very different.
"We’re all autistic but we present differently," explained Locke.
"Everyone’s autism is different, just as we look different, our brains are different, how we mature is different and how we cope with it is different."
Fiona O'Leary, 44, from West Cork, Ireland, agrees.
"If you’ve met one person on the spectrum, you’ve met one person," she said.
"There are common traits but everyone presents differently, your personality plays a big part in that as well."
O'Leary, who is the founder of non-profit organisation Autistic Rights Together, has five children with her husband Tim - Dillon, 23, Vito, 11, twins Romy and Sienna, both 8, and Phoebe, 6.
Both Dillon and Vito have been diagnosed as being on the autism spectrum.
"My eldest son is very sociable and outgoing, whereas my younger son would find social interactions much more challenging, a bit more like me, I suppose," she explained.
"Social interaction for me is certainly the most complex issue of being on the spectrum."
Like Locke, O'Leary wasn't diagnosed until she was in her forties, after her children had received diagnoses.
"I got my hospital notes a few years ago and it was shocking to read them because it was obvious that I was autistic from quite an early age," she said.
"The lack of eye contact, the problems with social interaction, all of that was written down, but no one considered I might be autistic and I believe that is partly because I was a woman.
"When I was younger I had anxiety and an eating disorder, which are both common traits of females on the spectrum, but I wasn’t picked up.
"I was misdiagnosed and given medication - tranquilisers for anxiety - at the age of 16. These are serious medications with side effects, they didn’t help me at all because they weren't what I needed. It was kind of like putting a plaster on me.
"Getting a diagnosis at the age of 42 was very important for me, because I'd spent most of my life beating myself up. I was very judgemental and critical of myself. I didn't know who I was, and that's a terrible way to live. I developed anorexia as a teenager almost as a way of coping with the confusion.
"But the diagnosis explained a lot about why I am the way I am and I love myself more now."
"As a young woman, I, like a lot of girls was very self aware," O'Leary added. "Which is a good trait to have, but it is a double edged sword, because it means we know we’re different and we try our best to blend in, to mimic.
"We also internalise our feelings, which for me caused a lot of physical symptoms, like stomach pains and fainting.
"I'd taught myself to be quiet and not complain, because that’s what women do. So if I was in a stressful situation I'd never tell anyone I was feeling anxious, I’d just suffer.
"Trying to please other people all the time is exhausting, and that’s what it was like for me for me, being Fiona pre-diagnosis.
"As women, we try so hard to please others - to fit into the boxes they want us to fit into - that we neglect ourselves and we neglect our mental health and I think that’s really really sad, but that’s the reality of it."
Women who have developed the ability to "mask" or hide signs that they are on the autism spectrum may outwardly appear to be more integrated into society, but as O'Leary testifies, the effort involved takes it toll.
According to Povey, masking may be partly responsible for the high incidence of anxiety and eating disorders among women on the spectrum.
"Masking in itself can be very tiring and stressful," she said. "And is often linked to the development of secondary problems such as anxiety, eating disorders or depression, as well as increasing the chance of misdiagnosis."
Alis Rowe, 27, from London, was diagnosed with Asperger's Syndrome five years ago. She spent a lot of her formative years masking her natural behaviour.
"No one should have to pretend to be someone they're not," she said.
"Until I left university, I always tried to fit in. I would do things I didn't want to do, because I thought those were the things I was supposed to be doing.
"However, once you realise you are not 'mainstream' you realise that mainstream things are not going to work for you."
"In fact, the advice people used to give me to 'push myself' and 'go outside of my comfort zone' in the end made me a lot worse and probably led to me suffering from depression," Rowe continued.
"I know who I am. I was always very happy at home where I was allowed to be myself and do my own things.
"It was only when I was around others my own age, that I felt weird, abnormal, inferior and different.
"I don't fit in with what society defines a female to be. When you are younger this can make you doubt your self identity, your gender, your sexuality.
"Masking is very easy to do, you just copy others and it works when you are younger as social interactions are simple. But as soon as you reach adolescence and gain greater awareness of self and others, it starts to fall apart."
Rowe is founder of The Curly Hair Project, a social enterprise dedicated to supporting women and girls on the spectrum, which has put her in touch with thousands of other women with similar experiences to her own. This has led her to believe autism may be under diagnosed in women.
Povey concurs that estimates for the number of women on the autism spectrum are hard to pin down.
"There is no way of knowing the true discrepancy between the number of autistic men and women, the prevalence rates vary wildly between ratios of 2:1 to 6:1," she explained.
"Previously it was widely believed that autism affected vastly more men than women, whereas more recently, it is thought that the discrepancy in diagnoses may be due to women being better at masking the classic symptoms of autism, and presenting in different ways, making it harder for clinicians or parents to pick-up.
"Past research into autism has concentrated overwhelmingly on males, meaning that the way we understand the condition, culturally and clinically, tends to be based on the experiences and behaviour of men and boys.
"This reinforces the very male narrative of autism which has shaped the criteria used to diagnose autism, the type of support available for people and the public's perception of what autism is.
In this self-perpetuating cycle, which could be seen as a form of unintended structural discrimination, far too many women and girls go through life without a diagnosis or are misdiagnosed and miss out on support which could make a huge difference to their lives.
Nicky Clark, 49, from Shropshire, can relate to this. Clark and her two daughters have all been diagnosed as being on the autism spectrum. But getting a diagnosis for herself and her older daughter was far from straight forward.
"Diagnosing autism spectrum disorder is less clear cut for girls, because we’ll often be conditioned to present a mask," she said.
"It’s like we're a swan gliding on the surface of the water, but furiously peddling underneath.
"The stress of keeping all that peddling to ourselves, so as not to upset others, I believe certainly plays a part in why there is a high incidence of eating disorders and anxiety among women with autism spectrum disorder."
Clark's oldest daughter Lizzy, now 21, was diagnosed at 11 after an 18 month process of assessments - during which she was misdiagnosed with ADHD and given Ritalin.
Her youngest daughter Emily, now 18, was diagnosed at three. The process for her was smoother and Clark believes this is because she presented with more stereotypical signs of autism spectrum disorder - she didn't make eye contact, didn't speak and didn't appear to be in the present moment.
Having two daughters diagnosed at different ages means Clark has first hand experience of just how much difference early diagnosis can mean in terms of the support a child can receive.
"It's absolutely critical," she said. "Lizzy had no support, but Emily's diagnosis meant she was able to get support at first in a mainstream education and then in a specialist provider with a residential placement.
"Even with Emily's diagnosis it was difficult to get adequate support as services are underfunded, but without the diagnosis it would have been impossible."
Clark herself was only diagnosed in October 2015. She has found that people are often "surprised" to learn she is on the autism spectrum because her career as a disability rights campaigner and a writer with blogs hosted on The Huffington Post UK and articles published in the Guardian and the Independent, does not fit in with their view of what a person with autism can achieve.
"People say you can't be autistic, you're too creative," she said. "But actually drama school was wonderful for me, because after years of masking I was well practiced in acting - as I'd been being lots of different people, rather than my true self, all my life."
One reason Clark feels she had to hide a lot of her true character was because of a double standard in expectations about what is acceptable behaviour for a woman or a man.
"I do think I’m seen as difficult because of the way I react to things," she explained. "It was never my intention to cause trouble, but some of my behaviour was thought of as aggressive, whereas if I was a man it may have been considered assertive.
"When actually I wasn't doing anything more than saying here I am. This is who I am."
Clark admitted to feeling "some trepidation" about revealing her diagnosis publicly.
"People called me brave, which possibly highlights the jeopardy that is seen to exist for women with autism spectrum disorders," she said.
"But I just felt I had to divulge my diagnosis because otherwise I would be denying this part of myself and also a part of my children."
After spending years masking their true selves, Clark, Locke, O'Leary and Rowe all believe it is of vital importance that women with autism should no longer have to deny who they are.
Locke said her reason for speaking out about being on the autism spectrum was because she felt it was important to "stand up and be counted" and to say "we exist".
"My big hope, is to reduce the fear that women feel about admitting they have autism," she said. "Because the worst thing is struggling along and not getting any help."
O'Leary added: "That's why we need more than autism awareness, we need acceptance.
"When society as a whole accepts women with autism for who we are, then we can all truly be ourselves.
"We can be proud of being autistic."
HuffPost UK is running a month-long project in March called All Women Everywhere, providing a platform to reflect the diverse mix of female experience and voices in Britain today.
Through blogs, features and video, we'll be exploring the issues facing women specific to their age, ethnicity, social status, sexuality and gender identity. If you’d like to blog on our platform around these topics, email firstname.lastname@example.org with a summary of who you are and what you’d like to blog about