Natasha Linke, 25, Seaford Rise, from SA, shares her story.
Sitting in the specialist's office, I was surprised to see my doctor in tears.
'I'm sorry, but you're suffering from premature menopause,' she said, looking from me to my mum Susan, now 56.
Mum was fighting back tears too, but I was okay. After all, I was only 19 and the implications of what had been said hadn't really hit me.
For years my periods were irregular. In the last year of high school I didn't menstruate at all.
My GP had put it down to exam stress but when my cycle didn't return, she referred me to a gynaecologist and a fertility specialist. She now explained my ovaries weren't producing any eggs.
'We don't know why this happens,' she said. 'As you don't have a family history of premature menopause, it's probably just a random occurrence.
'If you ever want to have children you'll need an egg donor,' she continued. 'If someone you know will donate their eggs, you can use them, or you can go on our list and get an unknown donor.'
I tried to take in what she was saying, but as I didn't even have a boyfriend, starting a family seemed a long way off.
More than being concerned, I was relieved my recent weight gain, moodiness, hot flushes and exhaustion were explained and there was a treatment for them.
'I'm going to put you on the pill to give you the hormones you need and this should help with all the side effects of your menopause,' the GP said.
Mum and my half-sister, Melissa, 29, were more concerned about my lack of eggs. 'When the time comes, I'll be your egg donor,' Melissa said.
Her generous offer made me feel relieved. I wouldn't have to worry about finding a donor.
Less than a year later I met Matthew, now 25, and I knew I wanted to spend my life with him.
It was hard telling him I couldn't have children of my own but he took it in his stride. 'It doesn't matter to me,' he said.
Twelve months later we got engaged. At our wedding Melissa's daughter, Jasmine, two, was our flower girl and when Melissa had Liam four weeks later, she told me she was ready to give me the chance to become a mum too.
We had counselling sessions and then Melissa began injections to stimulate her ovaries to produce eggs.
In the meantime I had to stop taking the pill and begin medication to prepare my body for pregnancy.
'I'm so grateful,' I told Melissa.
'It's okay,' she said. 'I'm happy I can help you become a mum.'
Seven eggs were taken from Melissa and three fertilised with Matthew's sperm. Unfortunately, none were successful.
'I'm sorry,' Melissa said as we cried together. 'We'll try again.'
This time 15 eggs were retrieved and two embryos were implanted into me.
'What if it doesn't work?' I fretted. 'Let's wait and see,' Matthew said. Finally, the clinic confirmed that I was pregnant.
When our son Hudson was born I was overwhelmed with love.
'He's so beautiful,' Matthew said. 'He looks like you,' I said, surprised he didn't look more like Melissa.
Melissa was one of our first visitors and we hugged and cried. 'Thank you,' I sobbed as she wiped away tears.
Today Hudson is five months old. We plan to tell him the truth as early as possible. I want him to appreciate his loving and generous family.
As he grows up he'll know his wonderful aunty gave us a miracle - him.