Hello, and I hope I can help you today. I do not know how long ago you last did a home pregnancy test, but if you have not had sex since your last boyfriend and you has three negative tests for pregnancy since then, you are NOT pregnant, cryptic or otherwise. It is NOT biologically possible for you to be pregnant in that situation. And as I think you realize, if 9 months have gone by and you do not have a significantly bulging abdomen, unless you are so obese that you always have a large abdomen, a full term pregnancy would be hard to miss. So if you are anxious about somehow still managing to be pregnant in spite of the negative tests and signs, I hope this information is reassuring. However, what concerns me are your other symptoms of nausea, headaches and shortness of breath and increasing girth of your abdomen. I do not know how old you are, and I do not want to scare you, but these kinds of symptoms can be associated with certain types of abdominal cancers such as ovarian and colon cancer, as well as other GI related disorders. I strongly recommend you see an OBGYN doctor at least for an examination to make sure there are not any dangerous causes of your symptoms. They also could perform an ultrasound and a blood pregnancy test if there was any suspicion of pregnancy. If there is no gynecologic explanation for your symptoms, you may need to consult with a gastroenterologist as well. I seriously encourage you to see a health professional to properly diagnose and treat you. I hope this information answers your question and that you follow my advice and have a proper medical evaluation to make sure your symptoms are not due to anything dangerous. Best wishes, Dr. Brown