I'm 21f, still living with my parents bc jobs in this area are all parttime and I can't afford travelling to 2 jobs and cannot drive, hence why I'm stuck with them. I get God awful pain when it's "that time" alongside getting a bit lethargic and usual stuff. I'll often curl up and rest myself, sometimes using one of those lavender wheat bag things. It doesn't get so bad that I can't function but I will twist myself in unnatural ways to try and rid of the pain. It has caused me to pass out numerous times, however. 
My dad hates it when I try to take ibuprofen and the like and says I should only take it when I really need it and that I'm wasting it, but I do take them rather sparingly. I usually buy and stash my own painkillers so I can try to avoid being confronted about it, but we do generally have some in the cupboard for all to use too. But it's always obvious that I've heated up a wheat bag since it'll stink the kitchen out when microwaved. 

Non of us have any chronic pain issues, so the painkillers aren't super important in the house. I get muscular pains all down my right leg or my right shoulder due to some physical issues but I can usually avoid it with special exercise. It gets agonising sometimes though.
My mum gets lower back pain on occasion from labourous work, and my dad only ever needs to take painkillers when he gets headaches/migraines, usually after a lot of drink, or for muscle pain also from labourous work. But I'm made out to be the selfish one who wastes them. 

Tl:dr: my family don't like it when I take painkillers for lady pain, am I the asshole for needing painkillers to deal with the pain? 