What Is The Irregular Bleeding After Discontinuing Birth Control?

I have been on birth control for 15 years. i stopped 3 mnths ago. got my period(4 days late) but it was fine. obviously unpleasant like it was in high school. 3rd month it was late but i thought it wa sdone after 5 days but it keeps coming back. it has been 11 days now and i will randomly bleed. I have had a lot of stress...could that be it?