Hello ma'am and welcome.
From your query I would like to emphasise on the fact that you have been experiencing your periods, but just a little late? What about your sexual contact? Are you sexually active now and have you involved in unprotected sexual contact around 2 weeks prior to the date you saw the brown discharge or any time prior to that? If so, I would request you to first conduct a home
pregnancy test and check the result. If at all it is positive, there is a possibility of you having miscarried. Although this is just an assumption and needs confirmation from a doctor, please do go about the HPT (home pregnancy test).
If pregnancy is ruled out, then the cause is a
hormonal imbalance that can be triggered by a foray of causes like
stress, medical conditions relating to the reproductive system (e.g. ovarian cysts, etc.), chronic conditions (e.g.
diabetes), sudden weight gain or
weight loss, stress, medications, etc. Please do consult a doctor for a more elaborate evaluation.
Best wishes.