What Causes Irregular Period And Bloating?

Hi i am 23 yo. I have a history of slightly irregular periods, pms which includes excessive bloating. My query is that i got my period last in march and last month I just had a very dark brown period and light. Midcycle again i had dark brown discharge. Now am just bloating. Also, I the time around my period last month i had started exercising and also had exams. Whats going on! Height 5'3 and weight 144 lbs.