Help! What do I do........? D:?

Today i was home alone and my dog was whining by the door so i took my dog out to go to the bathroom (he was on a leash) and there were little kids outside. I kept him on a tight leash knowthing that he's protective of me. A little boy maybe around 3 years old comes up and tries to pet my dog without asking. My dog responded by snapping at him and he broke his skin. The kid started crying and his mom was flipping out. Then the dad comes down, and I explained how my dog has had all of his shots and how truely sorry I was. They still seemed very tense about it. I thought they were over reacting, but they said they want to talk to my parents when they get back. I'm so scared, what might happen to my dog even though he has had all of his shots?