Hi, I m a 27 year old female. I have been having mild, flu-like symptoms for the past 3 weeks now with frequent headaches , soar throats, body aches, and heart palpitations--although this may be a separate issue. I am not pregnant because I have had my period but I am at a loss for why these symptoms have persisted for so long without ever turning into a full-blown flue. What do you think are the possible causes for this?