You are right, that blood pressure reading is not normal in your case. But you should not be panic over 1 reading. Sometimes the technique of checking the blood pressure and even the apparatus may be faulty. Othertimes the person may be anxious while his blood pressure is being checked or he might have climbed a set of stairs and suddenly opted for checking the blood pressure without taking some breaths. Anyhow keeping all the possibilities in mind you are young and that blood pressure reading cannot be accepted as a normal for you however this high-normal blood pressure can be managed without medications by trying lifestyle measures first. I recommend checking blood pressure at home atleast 4 times a day and keep a record over a week, if still getting the same readings above normal average then correlate with the physician as further workup may then be necessary.
Regards.