hello, so I don't know what is happening

Emily • Hia, I am Emily. Trying to get through High School. I run XC and Track. And that’s it

So for the past month maybe? idk, but I have been getting really bad headaches, along with Stomach problems, and I have also going #2 alot more then usual. Sometimes I don't want to move, and other times I don't want to eat. I just turned 15, and my period started like 4 years ago. Is there any relations? Or can some1 possibly tell me what is happening? ?!!