Was anyone fluent before they started stuttering?

Was anyone fluent before they started stuttering? I started stuttering around age 12 which seems to be uncommon as most people seem to start stuttering as soon as they can speak. I could speak perfectly fluent until age 12 when I started noticing a mild stutter that got worse over the years. Not sure what caused it but it could be from increased verbal demands or even my autism. I have also heard stories of people stuttering at a much later age as well so its rather unpredictable.