Mononucleosis

I've had syptoms similar to cold/flu the past few days with headaches, fatigue sore throat etc and today I've notice a rash all over the top of my back. I know you shouldn't believe google but I have nearly all of the symptoms of mononucleosis (also know as kissing disease?) and the symptoms normally take around 4-7 weeks to show up, which works out about right. Do I have mononucleosis or is it something else?