spotting while on birth control ??

Titta • 27 years 🦂 With 2 perfect daughters 💕
So this is my 5th month of being on birth control and last month I was spotting pretty heavily the entire week before my period then I still had my period. Well this month im spotting again and I still have a week before my period.
 The other day I was a few hours late on my pill and a few days before that I had to double up on my pill cause I missed one could that be why though ? I normally take my pill on time so ..