Hi I am 20 years, a female, 110 and 5'4. I am healthy and excercise regularly, and started birth control three months ago although I am not sexually active and won't be until I get married in September. The last three months there has been random days were suddenly my stomach will become upset and in a half hour I will vomit, this cycle lasts for about six hours and then just stops. I am curious to what may be causing this upset? I haven't throwm up for years until this summer. I drink plenty of fluids and my diet eachtime this has happened does not match up, so I don't beleive it is food induced. Could it possibly be stressed induced?