birth control
"I am 19 years old and have been taking Tri-Sprintec for about a 1.5 years.  Haven't got pregnant thus far.  So I'd say its working wonders!  I know that on my last week on my birth control my period will come on a Tuesday to Wednesday.  It is so nice to know that I don't have to worry when my period will come.  I didn't have any complications my first few months taking it. Have never had weight gain.  A week before my period I do develop breast tenderness. About the only downside to it."