Plan B is not a form of birth control. I think it should be used if the condom broke, you have been on antibiotics, because they will effect the pill. Can I ask why you are not using condoms or why you're not on birth control if you're having sex? Eventually you will get pregnant using no protection.
Plan B messes with your body. Yes, I'm glad it's available. But why take the chance. I do agree with the above poster. See your Dr to find out if you may have an infection or if it's because of using Plan B.
I had that same discharge too after using plan b i just went to the doctor they never said if it was normal or odd but i sometimes still get it even though im pregnant now so what im guessin its oky but best is to go to a clinic so they can tell you