dui.. possible underage

my friend came to pick me up last night to take me back to his apartment. as we pulled into his complex, he got pulled over and the officers asked him if he had been drinking, he said yes and they performed field sobriety tests on him. they left me in the car and then came and asked me if i had been drinking [i had] but i said no and i didn't have my ID on me so i showed them my school id, said that i was 20, gave them my social and they told me to step out of the car and do a breathalyzer.

i must've tried like 4-6 times to blow into the device and i intentionally didn't blow hard so he couldn't get a reading. after the 6th time, of which i don't think he got a clear reading, he told me i was free to go and i left.

now, my friend got put in handcuffs, taken to jail and got charged with a dui. i'm pretty sure, but not 100% that they didn't get a clear reading from my breath test especially since the officer stopped after a few times and just told me i could go.

he didn't write me a citation or anything, i think they were more concerned with my friend's dui, but is there anyway i could get in trouble? i have 1 underage and 1 disorderly, i can't afford to get in trouble again.

If you did not get cited on the spot in that situation, it is very possible they are not going to charge you.