Blood pressure naturally fluctuates throughout the day and can temporarily rise when you're under stress. A few occasional high readings don't necessarily mean you have hypertension.
Your recent BP readings are within normal limits, so there's no need to worry. However, if you're still concerned and want to be completely sure, you can consider ambulatory blood pressure monitoring (ABPM).
This involves wearing a BP monitor for 24 hours, which records your blood pressure at regular intervals and provides an average over the day. You can get this done at most private hospitals with the necessary facility. You don't have to get admitted for this, it is done on outpatient basis.
That said, in my opinion, you don't need it right now. Just continue checking your blood pressure annually, and make sure you're relaxed and not anxious before taking the measurement.
Next Steps
Ambulatory BP monitoring.