I had a two day "normal flow period. then the next it was dark brown discharge and it completely stopped and then i spotted brown and it stopped.

Menstrual issues: Brown may be old blood. The main reason for light periods is a change in hormone levels. Causes for what seems to be a light period can include: thyroid problems, eating disorders, excessive exercise, initial periods for a girl, use of an intrauterine device, oral contraceptives, perimenopause & implantation bleeding in early pregnancy which rarely occurs.