Brown discharge can occur before, during, and after your menstural period. This brown discharge is basically, old blood that looks brown, but usually occurs as a result of the difference levels of hormones.
New research, now, suggests brown discharge may represents sign of yeast infection. However, confirm this first with your Physician or Healthcare Provider; if you use an over-the-counter treatment for yeast and you don't really have yeast infection, you might be creating your own personal race of drug-resistant super-yeast, and next time you have a real yeast infection it could be damned hard to get rid of.
Hope this answers your question!
REFERENCE(S)
1. Michigan State University, 2006.
yeast infection / symptoms
2. Sutter Health Network, 2006.
Vaginal Discharge