Missed birth control, do I use back up?

Alice
Okay, I am about 4 months PP. I am on the pill and last night and the night before I forgot to take my pill before bed like I always to (anywhere from 10pm-12pm) BUT I took it as soon as I woke up (6am) so it was only a few hours late. It was the first week of the pack too. Do I need to use back up???