My period lasts 6 days. what does it mean when it starts a few days late then ends after 3 days?

Periods: One expects minor variations in the menstrual cycle from month to month. Starting a few days early or late and lasting a few days less than normal is not a cause for concern. Birth control will help regulate if you want more cycle control. I see also have an eating disorder. This can dramatically affect menstrual cycles and hormonal balance. Addressing that is key