Yes, as Cuchculan said, my current fear is a mark on my record. RedfoxThomas, have you ever seen someone get a record from something like this? My mother was able to speak with the deputy at her school. First he said "it shouldn't be an issue, no big deal!" Then when my mother told him we were trying to avoid a criminal record he said "...Oh. Then you should hire a lawyer." He did tell us that some officers do something called "license plate bingo" or "bingo stops" where they randomly run the license plates of a car they can see. I have affixed the correct license plate and have double checked to make sure all of my paperwork is in order. Hopefully these things will play in my favor. It turns out I didn't need any tools at all; it just slides right in, I feel like an idiot.
If the police officers have any say in the matter I'm not sure if that will hurt or help me. When he first asked me why I hadn't switched the license plates I said I didn't even know how and lacked the proper tools. I thought he might have thought I was a car thief (he was treating me with a great deal of suspicion). I was just babbling-because that's what happens when I get scared. I'm now worried that I may have come across as someone who failed to follow the law out of laziness rather than ignorance. On the other hand, I'm pretty sure I was courteous, I do know that I thanked them for taking the time to explain the situation to me before I left to walk to the gas station to call a cab.
Again, thank you everyone for your wonderful replies. It really is very reassuring.