Not strictly PMS, but I used to get very sick while the messy bit of menstruation happened. I didn't need a calendar for it; I could tell it was coming because I'd literally feel mildly nauseous for a few days. Then the pain. Pain that made it impossible to lay, sit, stand. I used to hobble around the house bent over, groaning. I used to vomit from the pain. I cried to sleep those days.
This went on for years. School nurses accused me of lying as I writhed on sick bay beds, soaked in sweat and pale. Unable to keep pain pills down.
At 15, after realising I was losing days of education each month, regular as clockwork, my mother eventually took me to the doctor about it. I ended up getting the pill. Omg did that ever help. It's easier to cope with having a uterus when it isn't making you hate a quarter of your existance.
I'm on implanon now so I dont have to bother with pills, but it is fucking with my libido so I'm not sure what the next move is.