no, although it will be much harder for you too start now that you haven't been doing it from a younger age. It will take you a little longer to get into it in terms of physical strength etc but even adults can do gymnastics
I asked my parents to start gymnastics when I was 14. They told me I was too old to start. However, I believe that you can do it as long as you set your mind to it, work super hard and are in good physical condition.