What Causes Dizziness, Vomiting And Delayed Periods?

I used primilut N I had periods only spotting for 2 days but still I haven t my period yet but I feel empty stomach eventime even I ate a lot but feeling hungry , if i eat something i feel vomitting, in the morning feeling vomit with empty stomach...feeling dizziness while eating standing and sitting etc , headache feeling my inner muscles strech around belly button stomach I checked through pregnancy kit but result is negative. .. what s this symptom .yesterday I have brown sticky fluid and spots but no bleeding but feeling cramps pain in abdominal belly ... my last period had on 26july... plz guide me my HCG level is 25.25 what does it mean???