How Long Does Plan B Pill Give Protection Against The Pregnancy?

I am currently on the pill and this month I took it a little later (around 2 pm one day and around 11 pm) another day when I usually take it in the morning. Yesterday I had sex without a condom and he pulled out but I still don't know if any got inside. Also I already took plan b earlier this month, should I take it again, or should I be worried? Basically what should I do?