I read your question and I understand your concern.
That blood pressure value is a little high, however since it's an isolated event shouldn't be a cause for panic. At times it depends also on the circumstances at that particular moment, it should be measured after 5 minutes of rest in a seated position, not having taken caffeine containing beverages in the preceding 30 minutes.
For the moment I suggest non medical measures such as a low salt diet and regular exercise. In the meantime you should have your blood pressure measured more times in the following weeks. To make a diagnosis of hypertension at least 3 abnormal readings are required, only the one is not enough. If high values are obtained repeatedly and the lifestyle changes don't work then you should consult your doctor for evaluation and treatment.
I hope to have been of help. Feel free to ask further questions.