“I'd been on the pill for about 10 years, on and off but mostly on,” she says.
Now a mother of three, Carolyn says that the pregnancy really took her by surprise. “I was really terrified,” she recalls.
“I'd just finished six years of uni and was planning on focusing on my career for a few years. I'd also been partying pretty hard over the previous weeks so I was also worried I'd done some terrible damage to the baby.
“But I was 30, so felt like I had my life together enough to go ahead with the pregnancy.”
Now nearly 12 years later, Carolyn says that she wouldn’t change a thing.
But how did the pregnancy happen in the first place?
Stephen Robson is an obstetrician and spokesperson for the Royal Australian and New Zealand College of Obstetricians and Gynaecologists. He says that it is uncommon for the pill to ‘fail’.
However, he estimates that two or three women from every 100 will conceive while taking the pill.
“The oral contraceptive pill is very effective but not perfect - nothing is,” he explains.
Dr Robson notes that sometimes a woman will not absorb the pill dose properly, for example if they have a vomiting illness. In other cases women just forget to take it - this can be a particular problem when travelling, especially on long-haul flights.
Women like Carolyn who get pregnant while taking the pill worry about the potential harm the hormone dose from the contraceptive could do to the baby. But Dr Robson says data from studies shows that this isn’t a problem.
“The main issue is that the pregnancy has occurred at a time the women didn't want to be pregnant, and it can make it more difficult to sort out the due date accurately. But mothers and babies seem to be fine,” he says.
Dr Robson notes that if you do discover you are pregnant while taking the pill then it’s a good idea to see your GP as soon as possible.
“See a doctor promptly and make a decision about whether it is the right time, and you’re in the right circumstances to continue with the pregnancy” he advices.
While the pill is effective most of the time, Dr Robson says that it’s not for everyone.
“Some women experience side effects such as migraines, or acne and skin breakouts, or a feeling that their interest in lovemaking diminishes,” he explains.
Some women also face the risk of developing thrombosis. Dr Robson notes that is most common when a women is carrying excess weight, have high blood pressure, or have a family history of clots or thrombosis.
Dr Robson also notes that women who are forgetful might find one of the long-acting contraceptives, such as a Mirena or Implanon, more suitable for them.
For some women, getting pregnant while taking the pill comes as a blow.
Jenna already had two children and was in the process of moving house when she discovered she was pregnant.
“It couldn’t have happened at a worse time. We were living between my parents house and my in-laws and I had just started a new job,” she recalls.
Jenna suspects that the stress she was under at the time made the pill ineffective.
Sadly, Jenna suffered a miscarriage at eight weeks, which added to her distress. “I’m glad it’s all in the past, it was the worst mental state I’ve ever been in,” she says.
These days Jenna doesn’t take any chances – she has a contraceptive implant and she sent her husband for the snip.