anyways biteme I dont think you have nothing to be worried about. Then again If she said she's not on her period. One thing that I know that cause brown discharge is it could be a symptom of a myriad of vaginal infections (most likely not serious). If your really worried about it Go see a Dr.
The thing that you have to worry about is when the discharge has a yellow or green color, is clumpy like cottage cheese, or has a bad odor.
This is not april fools right if it is shame on you.