Cani get back into the airforce?

I was 17 at the time, went threw meps. I swore in but never signed a contract. I was not sasified with the jobs tehy offered me. So i backed out, got a discharge letter in teh mail (ZBD). Now that i am 20 i know what i want, and that is a nother chance. I want to no will i be aloud to get back in?