Paracetamol is a dangerous drug - yes. It causes horrible liver damage if misused. However, every single packet of the damn drug comes complete with the same warnings on the back:
1 to 2 tablets (500 mg - 1g) to be taken three or four times a day. Do not repeat the dose more frequently than every 4 hours. Maximum 8 tablets (4g) in 24 hours. Do not take for more than 3 days, unless your doctor agrees.
So by that token, I can take 1g of paracetamol every 5 hours I'm awake for the 3 days I have horrible period pain, and it shouldn't do me any harm at all.
So why do I think it will? and not take as many tablets as I should? and put up with the pain, even though period pain on top of my usual chronic pain pushes me from ok to irritable and miserable? It's not even as if paracetamol actually helps that much with the pain, but it's the only painkiller I can actually take - all aspirin derivatives are contraindicated for me, and codeine does terrible things to my gut.
Meh. Self-preservation instincts that lead to a failure to look after myself properly are just ... less than helpful.