I sat down at the local safeway and tested my blood pressure. First reading 147, second reading 132 and third reading 127. Is this accurate and which number is right?

I have tried this another day and get relatively the same results. My doctor previous to my own blood pressure tests said my blood pressure was a bit high so now I am monitoring this daily. However I am not sure if a concurrent reading is accurate? Should I take an average, low, or first reading?

any help will be greatly appreciated