Menstrual like cramps 10 min into running

10-15 minutes into my run, I get awful cramps that feel similar to menstrual cramps. They hurt while I'm running to the point that I have to stop and sit on the floor and hug in my legs till the pain subsides. If I'm lucky they go away in about ten minutes. I get them every time, regardless of where I am in a cycle. I ran cross country in high school and I never had this problem. When I turned 18 years old this started happening to me.
I've tried to solve the problem. I drink about 4 liters a day, so hydration is not the issue. I've tried running on an empty stomach and no luck. I even tried pushing myself less hard at the beginning of the run and I still got the terrible cramps. Last time I went out I took it real easy and got into a nice pace. When the cramps came I wasn't out of breath and my legs didn't even feel tired. I am now 19 years old, so I have been dealing with this for a year. I don't understand why my body is doing this as I eat very healthy and my fitness is way above average. I am very worried as this is not normal to experience such intense pain from just running 10 min.
Anyone out there that has a situation like mine? I know it has nothing to do with my digestive system.