Depends on whether or not you signed permission to allow the office to leave results on your phone; it would have been among the HIPAA papers you signed the first time you went there.
It’s interesting to see the way his healthcare is handling this. I have told my healthcare providers they can leave a message since I am the only one that can access the phone (hacking notwithstanding)
Even the automated calls require a press 1 if you are “patients name’ before they leave a message.