Hi!
Yes, if the timing coincides with your date of periods then your periods could be starting. If the discharge came mid cycle then it could be ovulation bleed. If you have been sexually active then another possibility is pregnancy.
Other causes of brownish discharge are hypothyroidism, cervicits (inflammation of cervix), vulvovaginitis (inflammation of vulva and vagina), hormonal imbalance, and stress. If the discharge persists or recurs (and does not coincide with your date of periods or ovulation) then please consult your doctor. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.