Hi My Name Is Delilah I Am 17 Years Old.

Hi my name is Delilah I am 17 years old. I have a question about birth control. I was on the inactive pill week and only 2 inactive ones then I took a blue one that was in the same pack because I thought it was stop my period. So then 2 days lasted I started a new pack and now my period is taking long to end. Why ??