Any value less than 0.01% has little meaning. It's in the noise of the test.
For information: They could run two identical tests from one sample of blood and measure PCR one log apart. That is a very large range. I would only be concerned if your PCR level changes 1/2 to one log upward. And then, would need a re-test to verify trend.
For all practical purposes you are "undetected" and to be honest will never have an issue with CML again. You beat the disease. It is done, finished, kaput as long as you continue to take your medication - in fact you should consider lowering dose so side effects are reduced as well. Congratulations!