Is it normal to have a one day period?

That is short.: Normal for a period is 2 to 7 days w an average of 3 to 5 days. 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.