After my period i have been spotting for 4 days and i took a pregnacy test and it came negative what could be the causing for the spotting?

Does not mean: anything. if it persists it means hormone imbalance. in that case your doctor can help you

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.