Can i switch service branches? (read the info)?

i was recently enlisted in the united states airforce and was set to leave with a job i didnt want so i am backing out. im set to sign my discharge papers within the next week. now my question is would i be allowed to switch and talk to say an army recruiter and enlist with them? i dont know if it would be allowed or anything so i was curious. im 17 and running out of options so quick answers would be better :)