I saw a flash after I went through a intersection in AZ. How do I know it was me?

I was coming home from working a late shift at the W hotel in Scottsdale AZ. I was on Scottsdale rd going southbound and a little after I crossed through the intersection I saw a flash. Not sure if anyone was behind me. I immediately looked at my speed. I was going under the speed limit. I honestly thought "what did I do?". I didn't see a flash in the front. It seemed to come from the side. I was also curious that if it was me, could i go to traffic school if it was a red light? Its very important to me because I am attending Universal Technical Institute, and this could majorly affect my future. Please help. Thank you.