I have brown period for 4 months for 3 days and on the 2 day i have a bit of red blood and i have lower stomach pain i'm 16 i usally have heavy period

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.

Periods: Please have your mother or someone to a Gynecologist. If you have to wait for a day or two you should have someone take you to the nearest Emergency facility. Hope all goes well!