Thanks for all of your advice! I spoke with the vet this morning and she said it was probably the microchip rubbing a little for some reason. As its not causing any discomfort to her, she said she will look at it when her boosters come round, unless it gets bigger, painful in the mean time. I also found out that she has won pet plan vet of the year! We have been going to Mrs Lucas for years, and when I was in St. Johns ambulance brigade when I was about 10, she taught us basic veterinary stuff! Go Mrs Lucas!!!
http://www.petplan.co.uk/Vetawards/p...vet_awards.asp