Talk to Gynecologist on Irregular Cycle

In last april my periods came after 2 months after that my periods became irregular and i faced heavy periods for a month. Then I visited thrice to gyne and simple cyst was diagnosed I used novadol tab for month and for heavy periods used transamine 500mg 2+2+2 for 3 days. Then i visited to gyne again and there was no cyst in scan but after that every month my periods come after 10 days , spoting for 4 days then heavy periods start and continue for 6 days means total duration of periods is 10 days. Now my que is what are the causes of early periods after 10 days . I asked my gyne she said no causes . What to do please guide me I m fed up and worried. I m going to marry soon in coming new year.