What Causes Early Menstruation With Dark Brown Discharge?

hi I have realised this month s cycle has come 3 days early started of dark brown 1st day pink blood clots 2nd day now watery to bright red bleeding. my cycle comes every 32 days and last for 3 days but this one is still continuing is 5 days now. I have been trying to conceive for 2 years with no luck a test on 2nd day of period is negative.