If you went to court and paid the fine, you were convicted.
However, it's possible that the offense was reduced to an infraction. If it was a misdemeanor, you would have been entitled to a jury trial and a court-appointed public defender. The judge would also be required to have you waive those rights before entering a plea.
I would go to the courthouse where this offense was filed and look at the court's file to see if you were actually convicted of a misdemeanor.
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