Periods coming early. Time. please help.

Hi Dr, I'm writing on behalf of my wife she is 29 years...She is overweight but had regular periods before marriage..we got married in Feb 2020.. After that she gained some more kgs.. For first 5 months her periods were regular. After that we observed there was a delay in periods, later we did pelvic scan found PCOD.. hence we undergone medications and weight reduction. We were prescribed susten 300, Ovabbles, Obimet, Letozole tablets..so taking those mediations she got periods on 35th day. Next month cycle last for 28 days and this month cycle last for 22 days... we expected either pregnancy or her periods to be on time...this is bit worrying that her periods cycles are getting decreased every month and unable to predict ovulation time... please help...