About a year ago I switched from Humulin N to Novalin N when I changed insurance coverage. Since that time I have had a few adverse 'reactions'. It starts almost immediately after I inject. It starts with a metallic taste in my mouth followed by muscle contractions in my chest and arms. Some mild difficulty breathing. Last for 5 minutes or so. I have discussed with my doctor and he thinks it is low blood sugar. I did have a very low reading one time immediately after the reaction but most other times it is normal or elevated. Anybody else have these symptoms?