My 11 week old shih tzu puppie got stung!~ HELP?

All we ever see in our yard is wasps, so I believe that it was a wasp, could not see a stinger, it was on the side of her head , just under her ear. It swelled up about the size of a nickel...red with a white center, she did not have any reaction other than this, then the next day, it began to itch like crazy and she scratched it tell it popped and oozed and bled. I cleaned her up, applied neosporin for infection and made a little Elizabethan collar , so she could not scratch it again. (This all happened on a week end so no vets open of course, we have an emergency clinic, but it is $400 just to walk through the door, I have been there before!) So it is now Monday and the swelling has gone down a lot, and it looks a lot better, like its finally healing, do you think I should still take her to the Vet. She is very active, eating great, barking and playing as normal. Worried mommy!!!