What if I started my new birth control pill pack late?

Hi, I am on Yasmin and I had my period last cycle and normally start my new pack on Thurs. I was unable to pick it up until mon. (yesterday) I had using the pull out method Friday, Sat and Sun and Today Tues. I started my new pack yesterday. Is it necessary to take plan B? I have been on Birth Control for over 5 years. What are the chances of being or getting pregnant?