You may want to show this to your boss.
A recent study into the effects of period pain and PMS has shown how disruptive it can be to a woman's professional life.
A large scale survey of 32,748 Dutch women between the ages of 15 and 45, found more than 80% of women said they were less productive at work while feeling ill.
While a little under 14% said they take time off from school or work nearly every menstrual cycle, but only a fifth told their employee their absence was due to period pain.
"Menstruation-related symptoms cause a great deal of lost productivity, and presenteeism is a bigger contributor to this than absenteeism," the research paper said.
"There is an urgent need for more focus on the impact of these symptoms, especially in women aged under 21 years, for discussions of treatment options with women of all ages and, ideally, more flexibility for women who work or go to school."
While many women are led to believe that experiencing period pain is normal, excessive period pain can sometimes be a sign of endometriosis.
Dr Mike Armour from Western Sydney University in Australia told the ABC that a lot of young women "could identify some problematic menstrual symptoms, but a lot of them hadn't heard of or couldn't identify common menstrual conditions like endometriosis, polycystic ovaries or vulvodynia."
He added that normalising period pain "puts [women] at risk of really suffering from these conditions without realising it."
