What Causes Burning Sensation On Vagina And Brown Fluid Discharge?

Hi doctor, Help me i have this buring sensation up in my vagina feels like peeper sometime I feel otit and sometime I doesn t but whenever I finish urinating it burn so bad I discharge a huge amout of brown fluid I went to the toliet and when I take my panty off my panty liner was full with brown discharge a huge amount but I still have brown discharge but little amout I feel like cramp of period my breast hurts I believe my periods about to come since I suffer from irregular period so I don t really know help me