This is the kind of question that could only come up after hours upon hours of undisturbed solo driving.
When a female convert goes to the mikvah to complete her conversion, does she become "not niddah" after the mikvah? Assuming the timing is right, of course. Not that it matters, but it was an interesting question. Because can you have two intents when immersing or is immersion just an immersion that has all possible effects regardless of intent?
And along those lines, my understanding is the conversion mikvah dip has to be planned to be at the right time for female converts. I don't remember very much about planning my first mikvah date, although I know I had to plan to miss the actual "red" days, though I don't remember if I was told to avoid "white" days as well.
On a related point, what's the opposite of niddah? I may be having a brain malfunction, but I can only think of "niddah" and "not niddah."