Is my DUI dismissed or still pending to be filed?

This is my first DUI offense with no felonys or anything prior other than tickets. I wasn't given a ticket at the scene of the incident and never given one since. I was pulled over and blew a .08 right on the line after having only 3 beers and was by myself. That was November 24 it's 2 months later and few days and the DA still hasn't filed charges. Is there a reason why? How long do I have to wait? This does effect my sentencing whatever it is and or deferred sentence.