When Lucy first found out she was pregnant while sitting in a toilet cubicle at Sydney's Central Railway Station, she was in "complete shock".
"I'd just finished a lunch with my sister and I'd brought the test a couple of hours before and had been putting it off," the 26-year-old said on Tuesday night's episode of Insight.
"I'd had a few hours to kill before going off to work, and I thought, 'well, this is a great way to fill that time'."
Lucy, who assumed she was in the early stages of pregnancy, notified the man she believed to be the father. The pair, who met on Tinder, had been dating for around six months before they broke up and he moved to the UK.
"I was always taking the oral contraceptive pill [and] condoms were used sporadically," she said of their relationship.
"At that stage, I assumed it was in the early stages, and so straight away I was thinking of a termination.
"I told my ex what had happened, because at that stage my gut feeling was that he was the father and therefore had a right to know."
But after Lucy's ex-partner had moved away, she started casually dating another man who she also met on Tinder. After an appointment with her GP, Lucy realised that the man she'd been casually seeing could now in fact be her unborn baby's father.
"Initially, I thought [the father] was the ex," she explained.
"The GP gave me a blood test to give me a gestation period to determine what sort of termination I would have.
"Those blood tests told me I was eight weeks, so that then switched from my ex to the casual fellow I was seeing. He was really good and really supportive [about the news]. He provided half the money for the termination as well and offered a shoulder to lean on whenever or if ever I needed."
But in another turn of events, Lucy was thrown a curve ball when she went in to the examination room for her termination procedure.
"I walked in to the examination room, pretty much lay on the table and lifted up my top and the doctor looked at me and said there's no way you're only eight weeks," she explained.
"She then said she thought I was greater than 20 weeks, and 20 weeks is the legal cut off for terminations in NSW."
After being told her correct gestation period, everything changed for Lucy. Her gut-feeling of her ex-partner being the father was now looking accurate.
"He phoned me, we had an amazing two hour long conversation," she explained.
"The next morning I sent him a message just saying: 'Look I just want to say thank you so much for being so supportive and he wrote back and said: 'Well, I'm glad you feel like that because the next conversation we have will have a very different tone.'
"That's when the accusations started flying. After I found out how far along I was, I actually decided to go down the adoption route ... and I told him, and he was very on board with that."
Lucy said while she was going down the adoption route, she did keep in contact with her ex-partner throughout the whole pregnancy.
"He was very patchy with his communication," she said.
"He asked for a DNA test ... and I was offended. I knew that we were completely monogamous when we were together."
After giving birth, Lucy says it was the "weirdest week of her life".
"The hospital that I delivered at, they were aware of my intention to adopt," she explained.
"They were fantastic they gave me a private room, so I wasn't going to be surrounded by excited new families and pretty much said I could stay there — within reason — however long I like."
But after leaving hospital, and seeing her son two times a week to express milk for her newborn, Lucy's feelings about the adoption completely changed.
"I couldn't do it," she said.
"At longest there was four days in-between without seeing him. They were awful days, so I thought well if he's adopted, the most I will see him is four or five times a year. And I just couldn't do it. So I kept him."
Lucy said at the wishes of her ex-partner, she got a DNA test to confirm who was the biological father of her newborn son.
"It showed he [ex-partner] wasn't the father," Lucy told Insight host Jenny Brockie.
"I got the results in the mail and I opened it as if it was a shopping catalogue. No doubt about it. I called the lab saying is there any chance there's an inaccuracy. I did absolutely everything.
"This meant that [the father] was Tinder contestant number two."
Lucy said she was told that when your first ultrasound is done at a later stage, the dating period isn't completely accurate.
"Realistically I should've been told: 'OK we are guessing it's around this, but just to let you know it can have a window of a few weeks."
Lucy said when she contacted the man she'd been casually seeing, he had been "subconsciously expecting" a message that he was the father, after seeing photos of her baby on social media. But regardless, he asked for a DNA test.
"Father hasn't met baby, and he doesn't want to until he has that piece of paper in his hot sticky hands," she said.
"So I feel like once this is done, we can start dealing with the day-to-day reality of what this all means."