What Causes Delayed Menstruation Post Removal Of Nexplanon Birth Control?

I had my nexplanon birth control removed on November of 2014. I haven t gotten my menstrual cycle since having it removed. Monday, March 2, I bled very little and only lasted for a few hours. Didn t bleed on Tuesday and now again today, bleeding very little and light. Should I expect my menstrual cycle soon or could it be something else?