Hi, Thanks for the query. Irregularity in menstrual cycles and menstrual flow can occur due to many causes. Brown color of the discharge usually indicates collected blood. The possible causes for it are: - Indicating onset of menstruation -Intermenstrual spotting due to hormonal imbalance -Thyroid hormonal abnormalities leading to menstrual irregularity etc. So, possibly the spotting will turn into menstrual flow. If spotting prolongs, once consult gynecologist and get examined. With her advice go for investigations like ultrasound and thyroid profile. Possibly with this workup the cause for your problem can be identified and treated. Take care.