Blood pressure. Such things happen?

2 years ago I daignosed with PKD. So I got hypertension as side effects. Doc gave me telistaAM tablet daily after breakfast. I take my medicines regularly. But telistaAM gave me its side effect called Edema. So 1 month ago doctor changed my tablet to olmin trio 20mg. My swallow feet gone. we have automatic BP machine at office. I regularly check my bp weekly basis.Today after taking BP tablet 2 hours later I felt like gain I got low BP. So went and checked with automatic BP machine. Shockingly it came 150/110. And he placed the cuff on my arm with clothes. I felt something is definitely not right. Coz I had low BP feeling. And I took BP tablet just 2 hours bfr. I nvr get this high reading. Thn again I checked 5 mins later it came 110/70. And again I waited for 15 mins and thn checked with both automatic BP machine and manual mercury machine it came 110/70 i went to nearby hospital n checked with doctor it came 110/70. Agn i checked 2hours after lunch it was 110/70. Such things happen?