Irregular Periods

My periods are very irregular. Within the last year, they have gone from showing up every month and a half to now not even showing up every 3 months. My Doctor has me take pills to make my period come every 3 months. Any ladies that have struggled with this and have figured out a way to regulate the period cycle again? Any advice or recommendations? Any kind of help would be appreciated. My husband and I are trying to have a baby and these period cycles are not helping.