Hi. The pharmacist I go to has scales that weigh in kgs. For my initial weigh-in, the pharmacist noted everything down in kgs. The second and third times I went, the pharmacist was busy so one of the staff weighed me, but they have a guide provided to them for changing kgs into st/lbs. Ask your pharmacist to do this for you - it's the least they can do and won't take long to do.
With regards weighing yourself, 'they' do state not to constantly weigh yourself (which a lot of people seem to do). It's best to only weigh yourself once a week, at the same time of day, under the same circumstances, i.e. wearing the same clothes. Weighing yourself constantly isn;t a good idea and we get discrepancies that could make us feel worse - like weighing in at 6lbs difference. Try and find a pharmacist that has electronic scales as then it's not down to personal interpretation.