What Causes Irregular Periods With Nausea And Pressure In Stomach?

i'm 23 years old i had my period at the beginning of the month it was irregular for me since i was 13 i've had heavy cramps heavy cycle and only lasting 3 days this time i had a lighter period lasting 6 days i've been nauseas the last 3 wks as well as sore chest fatigue nausea at strong smells dizziness overly emotional pressure on my stomach at all hurts and makes me nauseas what could be wrong with me?