For about two days now, I have been feeling very bloated, dizzy, nauseas and having headaches that hurt my eyes as well as cold chills and a loss of appetite . I am also having alot of lower back pain , and most recently nipple tenderness. I used an at home pregnancy test, but got a negative result. This does not feel like period pain. However I am due to start within the next 2 weeks, I also just got new glasses, which I think is the cause of the headaches. Other than a pregnancy, what could this be?