confused

Mayra
So I'm 11 days late the last period I got was sept 29 I already took 3 pregnancy tests and they all are negative I also started taking the pill this is my second week. Is this because of the pill ? Maybe ? 
Update: I didn't mention this but when I started taking the pill I was already late by 3 days so what could it be? Should I go to the doctor to check it out??