C.V.
This is an interesting first question.
You decided that YOU want another child? Does the person you're sleeping with know this as well?
Plan B will screw your body up. Temporarily. The one time I took it, I didn't have a normal cycle for nearly 3 months. Read up on other women's experiences. It's normal because your progesterone levels are haywire.
I would recommend that you really need to think about what you're doing here. Either you and your husband (?!) are sure you want to have a baby together, or you stop trying and have protected sex until you are.