Can stress cause your cycle to stop? Almost 3 weeks late and negative pregnancy test results. Will an eptopic sp? Pregnancy cause negative results?

All can be true. Urine pregnancy tests are rarely negative if you are pregnant. And they are not specific for what type of pregnancy (normal, not normal, ectopic, etc). Stress, hormone imbalances, thyroid disease can all cause irregular periods. You should see your doctor to figure out which is the problem. Better to know and treat now. Good luck!
Yes and No. Stress can alter mentrual cycles and cause a missed period. A negative pregnancy test effectively rules out intrauterine or ectopic pregnancy although no test is perfect. If menses still delayed after another week, a repeat test would be warranted. If period doesn't return spontaneously-- see your doctor.