I stopped a ten day course of norethisterone (to stop continual bleeding - I'm 50) 4 days ago, but no bleed. How much longer?

7-10 days. A withdrawal bleed most often begins within 2 to 7 days after completing a progestin but can be as long as 14 days. If you are menopausal, a withdrawal bleed would not be expected. Abnormal bleeding at age 50 is usually evaluated by sampling the endometrium.