For me, the whole menstrual thing has to do with "shame". I was made to feel shame for a bodily function that is normal, bc my parent would not treat it as a normal, human need that needed to be taken care of. Instead, I was neglected or actively worked against in resolving a normal human progression from child to adult. Having been programmed to feel shame from the beginning of life by neglect and abuse perpetrated against me, the whole "becoming a woman" thing of beginning menstruation, was just one more thing used to create shame in me. (Bodily functions are shameful, and i am a worthless person who deserves no help or guidance)