hi, thank you for your query. what you re experiencing is called spotting. slight bleeding a week after regular menstruation is likely to be harmless: in teenagers the vaginal environment reacts literally to everything: air temperature, diet, rest and sleep regimes, stresses, acclimatization, etc. Menstrual spotting and stress have a deep relationship. If you are under a lot of stress, you may experience spotting during the middle of your monthly ovulation cycle. some causes are- -Hormonal imbalance. This factor often evokes shifts in menstrual cycle and unregulated bleeding of varied intensity. Intensive psychological and emotional distress or hard physical workloads can provoke imbalance of menstrual cycle. -Inflammation of the pelvic organs. This is quite a frequent cause of such spotting. Additional symptoms, you may have, include low abdominal pain, raised body temperature -other rare causes include endometriosis,PID,usage of OCPs it is a harmless condition,but if the bleeding persists beyond few days i would advise you to consult your OB/GYN. thank you wishing you good health