In the US, lab results are nearly always sent to the doctor who prescribed the tests, not to the patient. (And most tests cannot be requested without a doctor's order.) Some doctors are good about sharing the detailed results with their patients while others are not.
You can ask your doctor to send the results to another doctor (more often you just tell the new doctor to request them from the original doc). By law you are entitled to a copy of your medical record yourself but with many doctors it is surprisingly difficult to get them to do this. I have heard of cases where it took many weeks and the threat of a lawsuit.
Ostensibly, the reason for this state of affairs is so a patient can have a professional help explain and interpret the results.