Is it possible to stress out so ban cause you think your pregnant but all the test are negative an you miss your period because of stress?

In a way, yes: Might you be referring to pseudocyesis, or false pregnancy? In this condition, the woman wants to be pregnant so badly that her body develops symptoms of being pregnant: interrupted menses, swollen belly, enlarged tender breasts, weight gain, and even the feeling of fetal movement. Pregnancy tests are negative. http://www.webmd.com/baby/guide/false-pregnancy-pseudocyesis.