White coat syndrome. at doctor blood pressure was 136/92. i got a omron 10 machine at home is 109/66. possible to be much higher due to white coat?

Yes, very common: Your home readings almost certainly are more representative of your usual BP. You can check out the accuracy of your home machine; bring it next time you have BP in the doctor's office, or compare it with the one that's probably available in a nearby pharmacy. If your home BP is consistently similar to 109/66, you can disregard higher ones in the office. Keep a written record to show your doctor.