Did their diet make menses easier to clean? Did they eat their own menses as it contains many vitamins?
People with a penis need not answer
I was intrigued by the level of detail in the Earth's Children series and Jean M. Auel goes to great lengths to describe what amounts to the modern day equivalent of a belt and pad. I suspect that anyone living in the stone age didn't have the level of negativity surrounding a girl's period that we have today. I've never called my period a curse that's for sure. My infertility is a curse.