We’re fortunate to live in a country where women’s healthcare is mostly progressive and fair, where abortions can be obtained and contraceptives are free. But ask the NHS for a sterilisation in your 20s, and every door is slammed in your face. I should know: I’ve asked four times in the last three years and been refused every time.

The first time I asked for a permanent end to my fertility I was 26. I was recently out of a long relationship where we both agreed on a child-free life and back on the dating scene. Explaining my child-free stance to stranger after stranger was wearing, but made me think harder about why I’d made my choice. As I repeatedly explained, I’ve probably put more thought into my decision not to have children than many people put into their decision to have them.

The condescension came thick and fast: you’re too young, you’ll change your mind, who’ll look after you in your old age, how can any woman not want children, how can you be so selfish? Even people who only seemed interested in casual dating would instantly lose interest when I mentioned my disinclination to reproduce – one man walked away in the middle of a three-minute speed-dating session because I didn’t want to be a mother. Clearly, other people felt as strongly about my decision as I did.

Unfortunately, so did the first GP I spoke to. He trotted out all the usual comments (to strong opposition), followed by telling me he couldn’t “in good conscience” make a permanent decision when I was still “so young”. Having hoped for at least an in-depth discussion before being rejected, I was disappointed but not surprised. Resigned to another year of side-effects on the pill, I asked the GP to put a comment in my medical notes so I could build a stronger case later.

For the record, the reason I don’t want children is both simple and complex. I just don’t want them. I never have. You could perhaps attribute this to the fact that my mum actually had a sterilisation after I was born, but was talked into having a reversal and three more children by the man she married after my dad, since he didn’t have any of his own. She loves us, of course, but her energy and finances have been drained for more than 30 years by children. “I don’t regret any of you,” she says often, “but what you don’t have you don’t miss.”

Perhaps because of this, my family have never been surprised by or opposed to my stance on children. My mum fully supports it, as does my dad’s mum, who never really recovered from losing her son in his 30s. My siblings, one of whom has two beautiful baby girls, agree that my reasons are sound – and they’ve heard me express the same old opinion for enough years to know that it really is how I feel.

Friends have been less accepting. It can be crushing to think someone really understands you, only for them to suddenly say: “Yeah, but we all know you’ll change your mind.” People consider me headstrong and driven – the phrase I hear over and over is “she knows what she wants” – yet in this one area, they don’t believe I’ll carry it through. And in my weaker moments, I worry that they’re right. That I’ll fall in love and capitulate, like my mother did, and live my life a slave to children I resent, my dreams in pieces beneath their tiny trainers. It terrifies me.

I’ve explained all this and more to the doctors I’ve asked to sterilise me. When they’ve talked about the fulfilment that children bring, I’ve explained that I already have a longer list of things I want to do than I could possibly achieve in a lifetime. When they’ve told me I’ll feel differently when I find “the one”, I’ve explained that my “one” wouldn’t want kids either – and that I’d want to focus on being their partner, not the mother of their children. When they’ve casually called me selfish – more than once – I’ve explained that I’m a blood donor, an organ donor, a bone marrow donor, and even tried to give my unwanted eggs to childless couples – only to be told they’re not suitable because I’m a carrier for cystic fibrosis. Even this didn’t sway them. Reason after solid reason, and still they’ve rejected me every year since the age of 26. What are the magic words I need to say to convince a GP that this really is what I want?

After the fourth rejection, I was angry. Yes, I’m young compared with other people having the procedure, but not actually young. In every other aspect of my life I’m considered an autonomous adult. In fact, at 29, I’m considered old enough to be the mother of unlimited children, to create as many new people as I want without answering to anyone, and be trusted to look after them appropriately. But according to the NHS, I’m not old enough to know that I don’t want that, ever. It feels like a double standard: we’ll agree that you know your own mind as long as your decisions align with ours.

The doctors refusing to sterilise me have, without exception, been parents. Perhaps it’s uncharitable of me to suggest that they can’t understand someone genuinely not wanting a baby of their own, but they’re more than happy to prescribe me tablets, injections, patches and devices that achieve the same ends. They just won’t agree to make it permanent, at least until I’m “older”. What that means in practice no one will tell me – just that there’s some mythical age after 30 where your opinions become concrete and can finally be taken seriously.

It seems there’s nothing I can say to convince doctors that I’ve made my decision. More than once, they’ve expressed concern that I’ll change my mind later and blame or even sue them. I understand that, and would be more than willing to sign a disclaimer, but that’s not an option. Besides, how could I hold someone else responsible for my choice? Even if I suddenly reverse the opinion of a lifetime, I still have options. IVF can work after sterilisation, or I could adopt. I wouldn’t dream of haranguing the doctor who gave me what I’d been asking for. But it seems that fear trumps logic, and no GP wants to be the one to take the risk.

Usually, after I’m refused the operation yet again, I’m reminded about long-term contraceptive options. There’s a plastic device I can have put in my womb that’s actually more effective at preventing pregnancy than sterilisation, for instance. But it’s very painful to insert (more so if you’ve never given birth, ironically), is a physical imposter for five years, and gives out hormones that I’d rather not put into my body. The same goes for the pill, patch, injection and all the rest – I’ve never been able to find a contraceptive hormone that agrees with me, and I resent having to keep going back to the surgery to top up my infertility.

At the end of this year I’ll turn 30, and it means more to me than most. I’m hoping this will finally be the year I’m taken seriously in my desire not to be a parent. Yes, it’s a big decision, but one I made a very long time ago.