Chrissy, you take the pill to protect you from pregnancy. As long as you take it as directed, you are fully protected every minute of every day of every cycle. That does not matter if he ejaculates or not, or if you are having your period or not. Everyday.
Plan B is not going to add any protection. The only thing that can make it healthier for your reproductive health are condoms as well as the pill. Plan B will actually bring volatility to your cycle and cause all sorts of side effects for you.
Use Plan B if you skip a pill, or forgot to start the next pack. Even better, use a condom if you know you missed a pill or you are taking antibiotics.
Take care!