Interviewing & Disclosure of Arrest?

Hello,

Does anyone know the rules to what you are supposed to disclose during an interview as far as arrests for the Nurse Associate position (am a junior in school)? I was asked the question during an interview that is also standard on job applications, "Have you been convicted/found guilty/nolo contendre to a crime?" I said "no", but am wondering if this was the right response. I was arrested at a checkpoint over the summer for a DUI, but was not convicted at the hearing. I am on probation currently, and have gone to the required classes. My attorney told me that since I was not convicted, I do not need to disclose this information. I was not "charged" because it was my first and only offense of any kind. I am very embarrassed about it, but am worried that when the employer performs the background check my arrest will show up. Should I call the employer and speak with the HR person I interviewed with to clarify the intentions of her question in order to disclose this before it may display on the check, or should I stay still and see what happens? I am very concerned because this employer is my first choice and where I would like to remain in the future as an RN as well.

Confused & worried!