Did not mention a traffic ticket under $500 on N400 and on the interview. The Oath in one week. What to do?

Did not mention a traffic ticket under $500 on my form N400 and neither on the interview. The Oath will be in one week. What to do? The $80 ticket was given and paid 6 years ago. In instructions they say: "You do not need to submit documentation for traffic fines or incidents that did not involve an arrest or did not involve drugs or alcohol, if the only penalty was a fine of less than $500 or points on your driving record." So I was thinking I was not supposed to put it in N400. But after a few sleepless nights I started to concern that maybe I should and if so what to do and will my Oath be canceled for this reason?