Period 6 days late. Started light (for me.) Stopped in 2 days. Normally regular and very heavy for 5 or 6 days?

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 & implantation bleeding in early pregnancy, which rarely occurs.