I would give it more time. My puppy had a tooth like that (the bottom right canine, on the left in the picture) and it stayed put until he was over 7 months old. I played loads of tug and fetch with him, and the tooth popped out when I was getting his trick title. Blood everywhere, but we were happy for multiple reasons that day.
My pup has the same thing going on right now. I've found a number of her teeth over the past couple of weeks, and she's so miserable. Let us know what the vet says. I'm hoping hers will come out on their own in time.