What Causes Irregular Periods?

Hi..m 27 .single .my period is regular by date.but from few months m getting periods n an unusual way..in the sense first 2 -4 days pain with blood tinged offwhite secretions coming and by fourth day it starts bleeding wt severe pai,vomiting,bak pain,etc.and this time I got bleeding today morning..t was fourth day from begining of the series.morning while changing,I saw pinkish smal irregular flesh like matter along wt whitish pink discharge along wt 2 0r 3 drops f menstrual bleeding.. M not on any medication.previous history of passed out renal calculi.and I had intercourse wt my husbsnd( unprotected) 13 days aftr my last menstruation. LMP - 11/5/2014. Nw again next cycle from 11 june 2014. Pls do reply..wats the health problm from ur aspect?