What Causes Hot Flushes, Nausea, Dizziness And Cramping?

Hello. For several days now I have been experiencing hot flushes. Once this occurs I get dizzy and sometimes experience nausea with these. I also expereience nausea without these symptoms. I also have stomach cramping and the last few days have had more discharge than I normally would have. My last period was on the 9th of April 2014 and that finished on the 12th of April 2014. Since the day I started my period at 9 years of age it has been irregular. I am now 20 so this doesn t particularly concern me as I can get it one month and skip it for 6 months. Before April this year I had not had my period for 3 years. But I did experience spotting for only a few hours 3 days ago. Just curious as to what it may be? Kind regards, Kristen