Our 4 and 1/2 month old wheaten terrier puppy was playing our in the yard with our son and she smacked into a fence post. She immediately yelped loudly in pain and at first didn't put any weight on her right front paw. I've pushed on it and felt it all over and she doesn't seem to be in any pain and she is walking on it with full weight. She just shook her head and yelped in pain again so something is definitely wrong. It is Sunday late evening and all the vets around are closed. Thinking she has a sprain. Any advise would be appreciated. Thanks!