That's a tough one. I have great respect for the overwhelming workload our doctors have, but also get wanting to have the results reviewed with you in a timely manner. Perhaps try talking to his nurse, leaving a message for them, explaining that you are having difficulty reaching him and that you want to discuss your recent lab tests . Also remember that some tests take longer to come back and they could be waiting for those tests, to get the full picture.
But if this problem continues and is a persistent complication for you, getting a new doctor is always an
option for you. Hoping you get to speak to them soon.