Getting off-role instead of main-role

Am I the only one getting my 2nd choice more than my main role? I've chosen adc as main-role and jg as off-role. In my last 10 games, I've been jg 7/10 games and my last 5 games has been jungle only?? I'm d3 atm and I can't even play my main role when I want to. Can anyone with more wisdom on this subject lecture me a bit? :)