My period was 2 day late and lasted 2 days then brown discharge, am i pregnant?

Light/ late period: The main reason for light periods is 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. The best way to rule out pregnancy for sure is with a pregnancy test.