The purpose of basal insulin, whether your own or exogenous, is to keep your blood sugar in the normal range when you are NOT eating. So you want to begin the test in the normal range, then test frequently to see whether it stays there or not. If you inject bolus insulin during that time, you have no way of knowing whether the resultant lowering of blood sugar is due to your basal function, or the bolus you took. So the test would not tell you what you want to know.
Check with your doctor before proceeding (always!), but I strongly suspect that in order to have a valid test, you need to be (a) eating nothing, and (b) using no exogenous insulin.