Over-time compensation

I was hired as Administrative Assistant to the Superintendent of Schools and the Recording Secretary for the School Committee. I work a 40 hour work week in my position as Admin Asst to Supt. I am required to attend and take minutes at all school committee meetings which are held in the evening and last generally two to three hours. Monthly meetings are scheduled in advance and special meetings are added to the schedule. In the past four months we have had an average of three meetings a month. I have not received compensation (over-time) for these meetings. Am I exempt from receiving compensation for the additional work beyond my 40 hour week because the positions have been combined?