When Anna Spargo-Ryan went shopping to buy things for dinner one night, she noticed that there seemed to be pregnant women 'everywhere'.
"Prior to that it hadn't occurred to me that I might be 'in the club' too," she says. "But, as soon as I stopped to think about it, instinct told me that I was."
"I brought a pregnancy test there and then in store, and got a positive result 10 minutes later."
With her second pregnancy, instinct proved her right again. But this time it was linked to food.
"I was sitting at my kitchen table and had an overwhelming need to get KFC. I hate KFC, but wanted it so badly that I started crying hysterically and couldn't be consoled," she recalls.
"I was thrilled too though because I was sure that it meant I was pregnant. It turns out that I was."
Jess Bartlett had a similar situation with both of her pregnancies, and it was a desire to eat lemon crepes on both occasions that convinced her she was expecting before she ever took a test.
And for Sarah Yip an extreme sense of smell and nausea had her guessing.
"I could smell mown grass from blocks away, felt like I had gastro and could not stand enclosed spaces due to the stuffy air," she says.
"I also knew I was pregnant because I was eating mainly vegan, then developed an overwhelming craving for beef sausages," she adds.
So is it possible that some women intuitively know when they are pregnant?
According to Melissa Spilsted, a childbirth educator and Director of Hypnobirthing Australia, the answer is yes.
"I've been told countless times by mothers that they knew they were pregnant from the moment they conceived," she says.
"I remember one mum telling me that, after trying to conceive for many years and booking in to start IVF, she and her husband made love and she immediately said to him, "I'm pregnant. I just know I am. Turned out she was absolutely right."
Spilsted believes that, whilst many put these stories down to 'coincidence', there is more to it than that.
"There are many mysteries surrounding pregnancy and childbirth, and this is just one of them. But I do believe that the power of the mind is immense, and every thought we have creates a physiological or chemical change in our body," she says
Spilsted adds that our intuition is often quoted as being our 'sixth sense'. It's a sense that we don't completely understand and cannot necessarily explain, but that doesn't mean it isn't there.
And it's the same when it comes to birth.
"Intuition can definitely come into play during birth if a woman is feeling that something isn't quite right," says Spilsted.
"It could be her intuition telling her that her baby isn't in the right position or could be in trouble, despite others in the room stating otherwise."
"Or it could be a feeling that interventions are being unnecessarily imposed or suggested. It's surprising just how often mothers discuss these situations with me afterwards, and how often they are right."
Midwife, Kylie Lannan, agrees that hormones can have subtle effects on women, meaning that some can 'feel' pregnant before missing a period.
However, she isn't convinced that women feel symptoms as early as conception.
"Usually it takes a week or two for a woman's hormones to increase to a level where they have any effect," she says.
Lannan says that women who are very in tune with their body and its cycle may know intuitively they are pregnant by noticing or feeling subtle differences at this time.
"In my experience, this is more common in those who have been trying to conceive for a while and therefore they track and monitor every symptom and feeling," she adds.
Lannan says that the most commonly reported early symptoms include a "feeling" women get, sore breasts, going to the toilet more than usual, extreme tiredness and being emotional.