Tab.Metformin500 one tab twice daily.
Have intercourse on alternate day from 12 th to 20 the day.as ovulation occurs midway between two periods.Periods being irregular you have to anticipate the fertile week.
You can keep the daily body temperature record before leaving the bed in the morning ,it is raised by half to one degree on the ovulation day & accordingly you may try to concieve having intercoursethat week
Next Steps
consult direct, if required