Couple of questions. Have you have unprotected sex? If yes, time to take a trip to the drug store for a pregnancy test. Next have you or are you losing weight without trying? If so, Go to the doctor immediately. Are you eating regularly or have you changed your eating habits in the last two weeks? If so, Your body doesn't like this so cut it out and eat better. And finally are do these feelings include indigestion or heartburn? If so, again go to the doctor immediately you may have acid reflux or you could be developing an ulcer. Both need medical attention.