Applying for citizenship with a DWI record

So my story is that I've been a permanent resident since 1999 when I was 14 years old and resided in New Orleans, LA with my mother who married an American citizen. I've always been a good student but I got arrested twice for DWI in New Orleans when I was 18 and 19 years of age (so it must have been 2003 and 2004). I only got convicted of a misdemeanor the second time because the first charge was lowered to a juvenile DWI arrest and I payed to get it expunjed from the public record. Now I reside in Connecticut but last year 2007 I got arrested for a DWI again but this time in the state of NY. They never found out about my previous arrests since my drivers license is from a different state now and I guess it's been 5 years or so. So the charges got lowered to a violation called DWIA (driving while ability impaired). I finished all of my court orders already and now I'm looking to apply for citizenship since my green card expires in 2013. What should I do? I know that I have to be honest and that they can find any records on me unless they all got burried somewhere by Hurricane Katrina. Any suggestions?