No. The Plan B will however mess your next cycle or two up, causing out of sequence spotting and bleeding, and likely no bleeding when you expect to.
The pill protects you every minute of every day of every cycle, active or inactive. AS LONG AS YOU TAKE IT AS DIRECTED.
I think your confusion comes from this: "I know its possible to get pregnant anytime there is intercourse". This is not true. You can only get pregnant when you ovulate. The pill however stops you from ovulating altogether.
Unless you are in a long term relationship, it is wise to use the pill and a condom. Using the pill, a condom and Plan B is just an overreaction to a risk that does not exist.
Take care.