Hello,
Brown discharge is common in women with irregular menstrual cycles.
Discharge can not be due to sexual intercourse.
When ever there is a change in a bacterial flora in vagina, there may be a smell.
It is not necessarily to have infection.
You have to concern if you have itching, frequent discharge and
redness or swelling in vagina.
Thus nothing to worry about.
Please follow some basic hygienic measures
1. Keep the vagina clean by washing regularly
2. Use gentle, mild soap and warm water.
3. Never use scented soaps and feminine products
4. Wipe from front to back to prevent bacteria from getting into the vagina.
Hope this helps.
Please write back for further queries.
Wishing you good health.