I usually start my period right on time, but 12 days before my scheduled period i started bleeding. it is very light. i haven't needed tampons, just a pad, but it only makes it to the pad a little. no cramping ( i usually get moderately painful cramps.) i

Irregular bleeding: 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. Infections & hormonal changes can cause spotting. If there is a concern for pregnancy then do a home pregnancy test . There are many options available to help regulate the menstrual cycle. Schedule a visit.