Has Anyone Had This Issue?

Hi! For context, I am 20 years old and have NEVER had this issue before.

It started about a year ago. When I run a certain distance, I get these debilitating cramps that seem to originate from my uterus. They're pretty much the same place I get cramps at when I'm on my period, but on the pain scale, they're so much worse. It's increasingly concerning, especially since I'm in the military and have to pass a PT test every 6 months. I have always just stomached the pain and ran every time, but it seems like it's getting worse every run.

I also recently started having extremely painful periods, where the first day of my period has me on the floor, seeing spots in my vision. I will often feel light headed and start to have cold sweats. The only thing that seems to keep me from feeling this way, is a heating pad that I have to keep on for at least 30 minutes. After the first day of my period, I feel no pain at all, and have minimal discomfort. I have tried taking an iron supplement a week out from my period, which helped significantly. But anytime I forget to take it, the pain for the first day of that period is absolutely unbearable.

I do have a doctor's appointment scheduled, but it's not until November. Hoping for some kind of insight.

Thank you!!!