Why do I feel so unbelievably unwell on my period? I’ve had ultrasound scans and blood tests which have all apparently came back normal

But whenever I’m due my period I can always tell without looking at the date, I’ll get really emotional and very irritable. My legs will start getting very sore as if I’ve been walking miles. My cramps are absolutely unbelievably sore. They’re debilitating. The occasional nausea is unreal as well. Also the occasional shoot of lighting hot pain up the backside 😂 the BMs can be really painful as well.

I’m a nurse and whenever it’s that time of the month I find it really hard to focus and do my job because of the pain. But apparently everything’s came back normal so I’m at a loss.