I stopped eating meat and have noticed that my gums are becoming very light, pale pink in colour (this is not a build up of plaque), is this anaemia?

Not necessarily: This is not necessarily a sign of anemia. Check if the inner lining of your under eyelids are pale and if the palms of your hands look pale as well. The best way to tell is get a blood test. If you are menstruating and have heavier cycles, then of course you are at higher risk of anemia.

May be: May be due to your change in diet, but may be indicative of other situations, such as reaction to Meds, insufficient protein or imbalanced diet, heavy period, etc. have your Dentist evaluate the health of your gums. Have your Physician review the balance of your new diet regimen.