It sounds to me like you got married here in the United States, years after you originally came on a student visa. Even if your marriage in the U.S. was not civil, but rather religious (which alone is not recognized for immigration purposes), you still should be fine. Fact is that you did not enter with any intend to deceive from what you describe.
As some of my other colleagues have suggested, however, you should consult with an immigration attorney and have him or her accompany you to the interview, just to make sure you're covered. Most USCIS officers will see there is no issue, but you always run the chance of ending up with one who has a hangup about marriage cases.