I started lightly bleeding like fresh blood 3 days after my period had ended! what could this be?

Irergular periods: Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. There are many options available to help regulate the menstrual cycle. Bleeding right after a period usually just means there was blood in the back of the vagina that needed to come out