Thank you for your reply!
My blood glucose levels have been good, and I don't have any other symptoms of my ketones being too high but I will definitely investigate the blood testing strips. I see my GP regularly so I will mention this. From my quick googling it did seem as if it was fairly normal for a low carb diet, but it's always good to ask others who might have experienced it too. My diet isn't extremely low carb and I'm still getting lots of veggies and fibre etc., I've just essentially cut out bread, rice, pasta etc as they were really causing my blood sugar levels to rise and I've noticed a dramatic drop since I started watching my carbs. Really hoping to reverse this when I come off the steroids!