If getting checked at the doctor's office makes you nervous, then you may be relieved to learn that you are not alone and it even has its own term: "White coat syndrome". For this reason you should be wary of the results that may indicate that your BP is on the high side. If there is any suggestion of the need to go on medication, insist on self-monitoring your BP at home through the day over a few weeks using a digital BP monitor such as an Omron.
The doctor's office measurement of your blood pressure is a snapshot which can be misleading and may lead to unnecessary medication. BP fluctuates during a 24-hour period. BP peaks during the daytime hours, and can vary with work and activity. It can also surge during stressful events. For some people, this includes when a doctor or practice nurse applies the BP cuff.
If your BP is elevated, there are nutrtional and dietary measures you can experiment with; but bear in mind that these take time to kick into gear. You must be patient and medication may need to be taken during the interim to protect your cardiovascular health if BP is excessively high.