Dear Welcome to HCM We understand your concerns I went through your details. I suggest you not to worry much. I sincerely suggest you to ignore the symptom. Apprehension and anxiety symptoms include nausea. It can be termed one of the reflux actions of the body and is part of fight - flight syndrome. Such a reaction must have been manifested to you as an obsession and therefore you feel it always in such occasions. You had that disturbing sensation once. You expected it to happen again and tried. Then you started experiencing it as you were expecting it. Then your body brought the familiar symptom because you are expecting it. Then you started worrying that the symptom is coming again and again and expect it. Body brings it again as you are expecting it. You become worried and so on. That is obsession in simple terms. Ignore it and the problem vanishes. If you require more of my help in this aspect, Please post a direct question to me in this URL. http://goo.gl/aYW2pR. Make sure that you include every minute details possible. I shall prescribe the needed psychotherapy techniques. Hope this answers your query. Available for further clarifications. Good luck.