What Causes Delayed Periods,nausea And Bloating With Negative HPT?

21 YEAROLD FEMALE FEBS PER.WAS NORMAL ONE DAY THAN SPOTTED AFTER THAT,MARCH DIDNT HAVE ONE PER.STARTS ON THE 14TH OF MONTH TOOK PREG.TEST LAST NIGHT SAID WASNT PREG. HAS TIRED,THROWING UP NIPPLES HURT,MOODY PER LIKE SYSTEM THAT DONT LAST LONG WITHOUT BLEEDING CLEAR DISCHARGE FOR VIG. AREA