Lauren looked at her pregnancy test with joy. Within days, her baby wasn't a baby at all.

Two years.

That’s the rough age gap Lauren Knowles and her husband Trent wanted between their two children. They had their first, a little boy called Charlie, in 2012. By 2014, they were ready for another baby to join their clan. Their family was ready for it, their hearts moreso.

“We decided we wanted a two-year age gap, we didn’t have to try very long before we fell pregnant. We were delighted,” Lauren told Mamamia, recalling the moment she found out she was pregnant.

It was October 2014. A pregnancy test had come back positive, and a baby – a tiny, blink-and-you’ll-miss it baby, their baby – was on its way. Its heart would need to grow a little bigger, but it had already found its place in theirs.

At six weeks, Lauren began to spot blood.

"I wasn't overly concerned or nervous because my pregnancy with my son presented in the same way," she said. She made an appointment with her GP anyway. It was better, she says, to stay on the safe side. Peace of mind and all that.

That appointment, however, "was when the nightmare started".

Her GP ordered an ultrasound of which was "inconclusive", so the Perth mum was then referred to King Edwards Memorial Hospital for Women for a follow-up scan two weeks later.

As she lay on the hospital bed at eight weeks pregnant and looked towards the screen where her tiny baby came to life, Lauren Knowles was told she had had a molar pregnancy. She had no idea what that was, what it would do and what it meant for her future.

"I was completely baffled. I thought it was a miscarriage, and that was unfortunate, but I didn't think anything else of it.

"After I had gone home, I looked on Dr Google and found the worst information possible. It did nothing for my state of mind at that point."

According to the Royal Women's Hospital in Victoria, a molar pregnancy isn't particularly common, affecting around one in 1,200 pregnancies.

Listen: Mia Freedman interviews Bec Sparrow about love, miscarriage, and moving forward. Post continues after audio...

In a molar pregnancy there is unusual and rapid growth of part or all of the placenta. The placenta becomes larger than normal and contains a number of cysts and, in some cases, can become malignant and a rare form of cancer.

There are two types of molar pregnancies: a partial or complete. Lauren had a complete molar pregnancy, which is a type of gestational trophoblastic disease which forms when a sperm fertilises an empty egg - or an egg that has no foetal material in it.

In most cases, the tissue can be removed with a D&C, and can be followed up with some low-dosages of chemotherapy. Lauren, it turns out, wasn't most cases.

She was worst case scenario.

In the space of just a few weeks, the now 29-year-old mum had a positive pregnancy test in hand, and the next, she was facing cancer.

"I felt devastated, heartbroken, obviously. I had a miscarriage, but on top of that, I didn't even understand what I had. I had no idea what it was.

"I couldn't even explain it to my friends."

Of course, there are two edges to this. The first is mourning a baby that is now no longer, and the next is looking forward to a future where cancer is in the blueprint.

A post shared by rainbowsahead (@rainbowsahead_) on Sep 11, 2017 at 5:20am PDT

The kind souls at the hospital helped her through the former.

"[It] was really sad. They give you a pack, with a little candle and a keepsake for the little one that wasn't to be, which I thought was a really beautiful touch. It makes you feel like you're not alone."

The tumour itself manifests in a similar way to the pregnancy, which only added to the strain, the confusion and the devastation. Something is growing inside of you, but it's not your baby.

"I had a tumour all over my uterus, it was growing through me. I felt really strange about that, there was meant to be a baby in there. I felt pregnant and I looked pregnant, but I wasn't. It was a tumour. It was like a cruel prank."

Not only do molar pregnancies look like normal pregnancies, but the symptoms are remarkably similar to all the other usual symptoms women experience in early pregnancy.

Though most women who experience molar pregnancies can destroy the tissue with low-dose chemo or a D&C, nothing was proving to work for Lauren. And so, in January 2015, she found herself on an oncology ward, hooked up to a live drip for three days a week, chemo pumping through her veins.

A post shared by rainbowsahead (@rainbowsahead_) on Jul 4, 2017 at 6:39am PDT

"I knew I had a good prognosis, but being on the oncology ward surrounded by people who were dying made things so confusing."

If three months of that treatment wasn't hard enough on the body and the mind, at the end of February, 2015, and nearly four months after she was told her pregnancy wasn't viable, Lauren had to give birth to the baby that had grown into the tumour.

"I had carved a place in my heart for that baby. I had a place for that baby in my mind.

"It was painful. I will always remember the pain. I knew it was a disease from the beginning, so I knew I had to get my head around that quickly. I had to move on from that - that now I was being treated for an illness."

Some 12 months later - a whole year after finishing her chemo treatment and having to birth that baby that wasn't to be, miraculously, Lauren fell pregnant.

"A couple of months after my all clear, I fell pregnant. I was so terrified. I just thought it was going to be a molar pregnancy again. That fear that I was that one-in-however-many once, so it could happen again.

"I didn't think my womb could hold another child."

Her fear, it seemed, was unfounded.

Baby Indi came into the world in February. A healthy, beautiful baby girl, unperturbed the "horror" Lauren's insides had seen the year before.

"The reason that I want to get the story out is to offer hope, because I actually had a baby after all of this. After all that chemo, after I lost my hair, worried so much about reproductive organs, after not thinking it was possible and constantly being told there's too much damage and I would possibly have a hysterectomy. I had a baby."

She was, she says, the "worst case scenario". Not every tale is like Lauren's, but then, if it is, perhaps hers can be a source of strength.

"We're great. We're happy," she says. Indi was "everything [we] had waited for".

Two years was the rough gap they hoped sat between their children. Little did they realise it would work a little bit like that, though with many hurdles in between.

After all, the little baby that wasn't to be now sits, age-wise, between Charlie and Indi.

Always a central part of their family.

If you would like to follow more of Lauren's journey, you can find her on Facebook here, and Instagram here.