PA underage drinking citation, please help!?

Please help, Last night i went to a party with three friends. one was the designated driver. When we were driving home the other person threw up all over the car so we had to pullover to help her and clean up. We were in an empty parking lot so after a few minutes an officer spotted us and pulled up. I did have a few drinks that night but i was sober at the point when the officer came. After the officer investigated he concluded that the other girl had definitely been drinking that night but was sure i was. Then all the sudden he took out the breathalyzer he first gave it to the driver and she was good. then he gave it too me and i blew a 0.026 . he did not ask me to take it he just gave it to me, not telling me any of my rights or what my options were. he did the same to the other girl as well but she blew a 0.111. Did the officer act wrongly not telling us anything can my citation get dropped due to his procedure? did he have a right to test me with no parents present? I am only 16 and i was the passenger in the car i was not belligerent or incoherent. Also if this can't get dropped before i go to court i plan on pleading not guilty.. since my breathalyzer was low and it was my only second time drinking. what does pleading no contest mean?