Hi and Welcome. Sorry to hear Chelsea isn't feeling well!
I have found that with puppies, like babies, it doesn't take too much to upset their tummies. If Chelsea seems to be feeling like herself in all other areas, I'm betting that it was the vaccinations and/or just the visit itself. Make sure she's not getting dehydrated with any loose stools though. Is she eating and drinking okay? Perhaps a little Nutrical?
If you are feeling at all uneasy, a call to your vet will set your mind at ease.
Someone smarter than me will be along in this thread to give you more advice, I'm sure.
