Is Stress Causing Bleeding Problems In A Teenage?

My daughter is 17 and has had her menstrual period since the 5th grade. She has been somewhat regular; however has had her period for almost the last 4 weeks. She has had a light bleed associated with cramps...enough to use tampons. She is an student athlete that also holds down a part time job. Not sure if stress is contibuting; however, I am making her her first gynecologist appointment; but I am concerned. Your advise will be greatly appreciated. Thanks!