I missed my period in dec. i have had period now for 10 days and still has not ended. how concerned should i be?

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.