green poo, overactive let down...

My babe is gaining weight just fine but last week has went from yellow diapers to runny greenslightly mucusy and extra gassy.  I always have one fed off one breast per feeding unless shebstill seemed hungry.  My diet hasn't changed any.   Should I maybe do two feedings per breast?  I just don't want to finish my supply. I'm not sure that I have an over supply but I do have forceful letdown