I need help with my DUI.?

I get pulled over for a DUI. The cop takes me to jail reads my rights and haves me sign papers that he read me my rights. I do my breathalyzer and he continues my paper work. He tells me that he is going to punch a hole in my license and attach a piece of paper to it but as soon as he sees my breathalyzer results he stops all the paper work and tells me that there is a slight chance i might not even get this put on my record. He never gave me a ticket or punch a whole in my license. Then he let me go and said that I will be receiving something in the mail in about a month or two. What does this all mean?