What Is Causing Irregular Periods?

marriage hue march 2009 ,concive 16 to 25 may 2009. delivery hue 6 feb 2010. period started from delivery day till 45 day.then dr gave me some medicine to stop. then my periods stoped for 5 to 6 month. from the april 2010 i am taking injection to control birth (my one depond) injection.then in sept again i had 22day periods then again dr gave me some medicine to stop. periods stopped.after that i got a period in aug2011and sept that is ok periods no problem in this periods. them from i took i pill tablet in month of oct. after one month i started period small amount. in every 5 day 10 day for two month continou.when i fead up with my periods. i take ETOSSIS medicine,after that i stop for 15 days.then heavy periods starts.after that i go for treatment dr advise me on 22jan2012 Trapie MF for 3 day .and NOVELON for 21 days.u/s of pelivs is done. every thing is ok.tell me what happen to me????????????????????????