The problem is that such hygienic things were not in the whole USSR somewhere before the 80's. In the 50s, it could have been any rag, just any rag, which was then simply washed and reused.
It's difficult for me to imagine choosing cambric fabric specifically for a reusable pad. It's a flat, tight weave--makes very nice shirts and other clothing--but seems like you'd want something more absorbent as a pad. However, if any old rag would do, then you wouldn't use your nice new cambric. I wonder whether there is anything else in the list of items that might have been used: possibly the cotton socks? They would be absorbent, soft, and the sort of thing that wouldn't be embarrassing to hang up to dry in mixed company. The list of items reports, "cotton socks, whole and torn, 25 pieces". Torn socks could be put inside a whole sock and then used as a pad.
At any rate, you've answered my question about the possibility of "evil as hell" mood being PMS--in my opinion, definitely possible!