My turtwig is at level 20 and its still not evolving why is that and i never cancel any of my Pokemon's evolution?

are you kidding me my turtwig is level 29 now im still in the grass near twinleaf town it still not evolving i don't press the b button during poke battle's and it's not holding anything. -(from the person who asked this question)

there is obviOSly a glitch in ur game