I'm 18 years old, a college freshman very far from home. Last time I had a period was in August and I have now missed it twice, and have always been very regular. Am sexually active but have never had unprotected sex (always with a condom). I have lost about 12 lbs in 7 weeks becuase of the bad food at school and I continue to exercise. I took 3 home pregnancy tests after my first missed period and all were negative. Is it the stress and change, or should I be worried about pregnancy?

if you want to feel better try to go to the dr to get a blood test for the pregnancy issue. the fact that your diet has changed, with not eating much at school can be a big reason for change in period. eating habits, and stress can effect your period.