Long period...is it normal?

I started my period on Nov. 28th and it stopped on the 7th of Dec. But I started bleeding again on the 15th and now its the 28th of Dec. I have been taking fertility drugs such as Vitex, Dong Quai, Evening Primrose, and another one that I forgot the name of, could these throw off my hormones? Also before I started taking these my periods were irregular. Should I go see the doctor, my period hasn't been heavy, I can go for four hours without changing my pad.