Menstruation is private
One weird taboo surrounding menstruation is the belief that menstruation should remain hidden. It is private and meant to be managed only at home. In many local settings, there are no private facilities at schools and a lack of proper menstrual hygiene products.
In the past (even today) many girls did not know what a menstrual pad was. They use fabric or cotton in their underwear to manage periods. This often cause leaking and then stains which are not supposed to be seen by any, hence the need for a girl to stay indoors during their periods.
In ancient times, women were segregated and often called evil at that time of the month. Some were subjected to bleeding huts where they were kept for the three to six days they would bleed; others were not allowed near their family as it was believed they would endanger their lives because of the curse on their heads.