My parents weren't in a relationship when I was conceived. Instead, they'd been having an on-again-off-again affair for about five years. They met at the television station where they worked in Newcastle-Upon-Tyne (UK) and the connection was instant.
As well as physical attraction, it was a meeting of minds and they enjoyed each other's conversation. My mother, in her late twenties, was single at the time and my father Brian, 13 years older than her, was unhappily married with five kids.
There were many times throughout the five years my mother tried to end the liaison, but they kept finding their way back to each other.
Then, in 1979 my mum found out she was pregnant and made the heartbreaking decision to end the affair once and for all. She had handled the emotional upheaval of a lover that came in and out of her life, but she didn't want me to have a dad like that -- so she moved from England to Australia where her brother was already living and never asked for any kind of support from my father (emotional or financial).
I think my father was relieved by this decision and for 17 years he kept my existence a secret from his wife and family.
I sent him a letter saying that I wanted to meet him and my siblings, and was coming to England with my mother in the summer.
I can't say exactly what age I was when my mother told me why I didn't have a dad to take along to the Father's Day assemblies at school because it is simply something I have always known. I am grateful that Mum never tried to make our story more palatable for me, but I can't deny that I thought a lot about my father and my siblings while growing up.
Mum gave me the few photos she had of my father and I treasured these dearly. She told me I got many of my physical attributes from my father's side and I wondered if I shared any other traits with him or my brother and sisters.
I wondered if my dad ever thought about me and Mum. Even though I knew they all lived in England, throughout the years I would often go somewhere like a cinema and find myself examining the faces of the people around me, wondering if they could possibly be related to me and not know it.
My mum never referred to my father as the 'sperm donor', although I have heard other single mothers use this term, but I can see the similarities between myself and those of donor children.
Perhaps this is one of the reasons I chose to explore the topic of egg donation in my latest book and while doing so I was fascinated to discover that although in some overseas countries eggs can be purchased, here in Australia egg donation is an altruistic exchange. A woman can give her eggs to someone else but she cannot receive payment for this and thus egg donation is considered a gift.
The lack of a financial reward helps ensure people don't donate eggs if they are not 100 percent mentally and emotionally sure of their decision. This law also means that the majority of egg donation exchanges in Australia are not anonymous. Donors and recipients might already know each other, because they are family or friends, or they have connected through online forums or through print advertisements and they get to know each other before beginning the actual process.
Most Australian states now have legislation enforcing all donors to consent to their identifying information being held on a register, so that the child conceived via their eggs can find out their genetic parentage once they turn 18.
Recipients are counseled prior to the egg transfer on how to tell their resulting children about their conception and genetic parentage. Many studies indicate that it is better for the child if they know about the egg donation from as young an age as possible.
I grew up without knowing my father personally but at least knowing identifying information about him. The mystery of my parentage was something that weighed on my mind during my childhood and adolescence but I felt a certain sense of satisfaction in knowing who my father was, even though I didn't have a relationship with him.
I always knew that one day I could track him down and find out more. Although my mum was obviously worried about the reception I might receive, she supported me in my decision and when I was almost 18 she helped me track him down.
Back then the internet wasn't the wealth of information it is now, so we used the international phone books at the state library to find his address. I sent him a letter saying that I wanted to meet him and my siblings, and was coming to England with my mother in the summer.
I wasn't sure if he'd reply and was unsure whether it would be a positive response if he did. For six weeks I stalked my letterbox and barely thought about anything else, yet when the letter arrived I was almost too scared to open it.
Somehow I found the courage and was a rewarded with a loving, positive response. My father was sorry for how things had panned out and I think also relieved that everything would finally be out in the open. He said he had finally told his family and he and some of my siblings were looking forward to meeting me.
My half-brother and two of my half-sisters took the news of an extra sister in their stride, but the other two were distraught learning of our father's affair and my existence 17 years after the event. Although in theory they didn't hold me accountable, they didn't want to betray their mother and felt developing a relationship with me would be hurtful to her.
In the end I did meet my father and all my siblings and it honestly felt like finding a piece of myself that had been missing all those years.
Rachael's book 'The Greatest Gift' is out October 23.