Most women experience period pain at some point in their lives.
For some, that 'time of the month' causes little or no discomfort, while for others it can be excruciating.
Most of us dismiss period pain as just 'one of those things' and get on with it.
However, it seems the level of discomfort you feel can be a warning sign of what level of pain to expect from child birth.
'The initial stages of labour are very similar to periods,' explains Dr Dasha Fielder, an Australia GP who specialises in women's health.
'Except with periods the pain stays about the same, whereas with labour it continues to increase and get worse until the baby is born.'
The reason behind the thinking is that period and childbirth pain are similar as they both originate from the cervix opening.
As with childbirth, menstruating also involves contractions.
Period pain occurs when the muscular wall of the womb contracts to encourage the womb lining to shed away as part of your monthly period.
During the heaviest days of our period, the cervix open ups to around one cms to allow the uterine lining to pass.
The continually contractions are usually so mild that most women can't feel them. But for some, this process involves cramping and intense bursts of pain.
During labour, the cervix needs to open not one cm but around 10 to allow the baby to be born.
'The initial stages of labour, when the cervix goes from around zero to five centimetres in diameter, are very, very similar to period cramps,' Fielder tells Mamamia.
'It tends to be in a cyclical fashion and the contractions come usually every half an hour or every 20 minutes, and it does feel exactly like period pain.
'I have tested it three times with my children, so I can tell you as a doctor and a mother it's exactly right.'
She explained the pain comes from the many nerve fibres within the cervix.
Women can be quite comfortable in the early stages of labour and some won't even realise they are in labour at all, she added.
'It's quite normal for women to not come into the hospital until they're about four or five centimetres dilated.
'But when they get to seven centimetres, that's when they reach what we call the transitional phase, and from there, if it hasn't been a problem already, the pain does become quite uncomfortable.'