"Do you feel the same way that I do?" "I don't know, honey, give me a clue." "Do you feel as though our life is finally our own again?" I knew where my husband, Paul, was coming from. The previous four years of our life had felt like a quest - and, as the years had gone by, an increasingly desperate quest - to find a successful course of fertility treatment. In our desire for a baby, I had lurched from drugs to intrauterine insemination, from hormone injections to alternative therapies. And I can still remember conversations from an endless round of appointments: with doctors, with gynaecologists and therapists.

I'd been told that there was no physical reason why Paul and I shouldn't have a baby. And then I'd been told that there was a reason, that there must be a reason, that it was simply a case of tracking down that reason.

I'd been told that my hormone levels were normal. And then I'd been told that my hormone levels were abnormal, that I was deficient in some crucial-for-conception way.

I'd been told that I needed to relax, to forget about having babies, to let nature take its course. And then I'd been told that I needed to focus; pop pills, inject hormones, timetable "intercourse".

I'd been told that, at the end of the day, there was always IVF. And then I'd been told that IVF wasn't going to be an option for me, that in the unlikely event of it being successful, the pregnancy would end in miscarriage.

We'd been married for five years before we decided that the time was right to start trying for a baby. Up until that point, there had always seemed to be more questions than answers. Would we be good parents? Had we grown up enough yet ourselves? And anyway - rather naïvely - I assumed that there was no rush, that having a baby would be easy, that we just had to make up our minds to start trying for one.

And so I still feel shocked, sometimes, when I realise that - after being married for almost 12 years, now - "the baby thing" still hasn't happened for us and maybe it never will. I had always imagined that I would be a mum. One day. I had always imagined that my husband - the love of my life - and I would have kids together. One day. And although part of me still hopes that day will eventually come, not having children changed our lives immeasurably.

When the baby thing didn't happen, it felt like all my expectations about life had been turned on their heads. I had to rethink everything. I had always imagined that raising a family would be my major preoccupation throughout my thirties and forties. And if that wasn't going to be the case, what was? Who was I - what was I - if I was never going to become a mother? All the beliefs that I had held about employment and financial security, about property ownership and savings plans seemed largely redundant if we were never going to have to worry about university fees and moving up the property ladder.

Our decision to put an end to fertility treatment had been unanimous. Fertility treatment had left us feeling powerless and hopeless, as though we were on a conveyor belt of procedures that was very much "one size fits all". Fertility treatment had drained the joy out of our life, for a while. Both of us had grown tired of our relentless rounds of appointments: for investigative tests with frustratingly vague diagnoses, for treatment and recommendations that seemed to dominate our lives yet offer us little hope of success. I'd taken four cycles of the fertility drug Clomid. I was prepared to endure the drug's side effects - hot flushes and weight gain, dreadful skin and mood swings - if it helped me to conceive. But it didn't. And so I'd moved on to three attempts at intrauterine insemination. And I was prepared to endure feelings of vulnerability and indignity, powerlessness and humiliation - as I lay on a hospital trolley, legs spread, while Paul's sperm was injected into me - if it helped me to conceive. But it didn't. Deciding to have a baby together, something that should have been a source of great joy, had instead become a bitter disappointment. I felt like a failure, as a woman, as a wife, as a human being. I felt helpless and, as the months passed, as though time and options and hope had finally run out. For the sake of my sanity, the decision to say "no more" had really made itself.

But then we made another decision, and one that was just as unanimous. We had had enough of sitting around waiting for life to start happening. We realised that because we only had ourselves to worry about, we had the freedom to change our lives into whatever we wanted. And so we decided to kiss goodbye to our 9 to 5s and follow our dreams to the west of Ireland.

We rented at first, living off the proceeds of our house sale, buying ourselves some time. And we thought about what we wanted to do with the rest of our lives. My husband had an idea for a website; helping people to sell their property online. I'd always wanted to be a writer; my novel had been a work in progress for too many years. And without the limitations of the day jobs or the pressure of mortgage repayments, finally, we had the breathing space to get our ideas off the ground.

I remember feeling philosophical, one day, when we'd been living in Ireland for about a year. And I decided to make a list for myself, of all the positive things that involuntary childlessness had brought me. At first, the things that I wrote were muddled and it was difficult to see where the negativity ended and where the positivity began.

I have always wanted to be different, to stand out from the crowd. Words like ordinariness and routine, anonymity and mainstream are enough to bring me out in a cold sweat. And so maybe not having a baby is what makes me different, maybe not having a baby is what sets me apart from everybody else.

If I never have children, I will never have to face up to the possibility of being a less than perfect parent. I can focus on the opinions of other people, "such a shame that Paul and Isla can't have kids, they'd be wonderful parents" and never have to worry about being unable to live up to the hype.

If we'd had a baby when we first started trying, we would still be living in England now. Stuck in jobs that were unrewarding in every other way but financially, handing over our children to childminders so we could maintain the two incomes required to cover our mortgage, trying to keep up with a ubiquitous Jones family to whom we could barely relate.

And then I surprised myself. Once I had started the process of writing, a stream of pure and positive thoughts just seemed to flow on to the paper in front of me. I feel infinitely more mature and more grounded and more balanced now. My understanding of myself and my dreams, my hopes and my fears is better than it has ever been. I have been provided with a unique and valuable opportunity to get to know myself.

If we are ever lucky enough to have a child of our own - or if we decide to adopt, in the future - I feel as though I have the emotional intelligence to really enjoy the experience of parenting, to have with my children the fulfilling and loving relationships that I desire.

And, for the first time in my life, I am living for now. Not for a future moment when X or Y or Z may or may not happen. I am enjoying the moment. Finally, I have learnt how to make the most of every day.

'Pink for a Girl' by Isla McGuckin is published by Hay House, £9.99

How IUI works

* Intrauterine insemination (IUI) involves inserting sperm into the womb to coincide with ovulation, as opposed to invitro fertilisation when sperm and eggs are mixed in a laboratory

* The sperm are washed to remove the fluid in which they swim and the healthiest are selected before being put into a catheter and inserted into the womb

* The process is relatively painless and takes just a few minutes

* Some women may also be given fertility drugs to stimulate ovulation

* IUI is recommended where men have a low sperm count or poor sperm movement

* It can also be helpful in cases where antibodies in the cervix are killing off the sperm

* It is generally regarded as the first line in fertility treatment, with IVF being used if IUI fails

* The pregnancy success rate is around 15 per cent per cycle of treatment and is higher still for younger women

* Experts normally recommend that patients try three to six cycles of treatment