I miss 1 birth control pill in week 1 & the next day I took 2 pills, then in week 2 I miss a pill again & took 2 pills, do I need Plan B if I had sex?
You might not have 2. But if you want to be extra cautious this would be a good thing to do. Forgetting two pills in a pack in theory makes enough of a drop in efficacy that you might want to have a back up plan. You could also use barrier methods (condoms) for the rest of this cycle as an added safety measure.