Is this normal or not? i start my period every fourth week and it started on a third week. and its light for some reason, and all brown this cycle(with occasional clots of all sizes), and dull abdomen ache. doesnt mean i have too high iron?

Starting a full week early, it probably isn't a normal menstrual period, and the change in color plus clots also might be significant. Any new or unexplained vaginal bleeding should be examined professionally and so should unexplained abdominal pain -- and you have both. There are many possible causes, but at your age STDs are high on the list. See your doctor soon. Good luck.