It seems that women had less periods in the 17th and 18th centuries.
 Menstruation has always been a mystery to mankind.
In ancient times, Hippocrates (460 BC– 370 BC) and Galen (AD 129– c. 200/ c. 216) explained that because women led a more sedentary lifestyle, their bodies were less efficient than men's at utilising the blood that they produced.
The resultant build-up of blood and other waste in the female body must be eliminated through menstruation for the sake of their health.
By the 17th century not much had changed. And while normal menstruation was still considered a manifestation of female illness, failure to menstruate monthly was also considered a disease.
Lazare Riviere (1589-1655) wrote a whole anatomy guide about women's health in which he counted that the womb was the source of "six hundred miseries and innumerable calamities."
He was not the first, and not the last: in the 1st century Pliny (23-79AD) proclaimed menstrual blood to be poisonous; turning wine to vinegar; causing trees and crops to die; clouding mirrors; blunting swords; and dogs would go mad should they chance to taste it.
In the 20th century similar opinions were rife, with one, Freud, suggesting that menstruation is the “bloody sign of a woman’s loss of penis”; and it is a reminder of a woman’s “uncleanliness and inferiority.”
Freud was undoubtedly influenced by the fact that Menstruation was considered a Bad Thing far, wide, and throughout history. For example, menstruating women were refused communion by Christian churches, while in Judaism, Hinduism, and Islam sex is outright out of the question during menstruation.
Feminists would claim that this is another manifestation of male domination, but, as much as they might be right, I think they too would agree that menstruating is not much fun.