for the past 3 mths i have been having two periods a mth...it all began last year when i went to the gyno..i use to be on ortho tryclien (sp?) and i went to the gyno to get more but they were out so i got put on triphasil-28, well for the first 3 mths i had to periods after i started taking it..but i figured it was because my body had to adjust well i am now doing it again and i dont know why