Gus was the same way after one of his shots. I call my vet whenever I have a concern or question. I figure that is what I am paying them for and they put up with me.
Anyway, they said soreness is fine but to watch for swelling, fever, diarrhea. They also told me I could give him baby aspirin. You need to know what dosage to give for your puppy's weight though so you'd have to ask your vet. I hope Bridget is feeling better.