Ok so i have been on my period for about ten to twelve days but the last three days have been really light... usually i'm on my cycle for about 6 or 7 days. Do i need to go to the ER or go see a doctor? I just started taking yaz, and i just finished the very first pack and i'm still on my period. My doctor said its just some break through bleeding, and that my body isn't used to the hormones but i don't know if its normal for it to last this long? Im concerned.