It is most possible that you will get strange or unwell feelings from a reading of 13, when i get high, i feel a bit stupid, sleepy and feel sick .... oh very very irritable :evil:
You can buy test trips from any chemist , although they can be quite expensive. You should be able to get a free test monitor from your local diabetic center, which will come with a few strips to get you started. Id pester your doctor or even the nurse at your health center, sometimes the nurses can persuade the docs far more easily than the patients.