High BP. On Perindopril, Amlodipine, Bendroflumethiazide. Continue?

I am prescribed before for perindopril 4 mg combination with amlodipine 5 mg, for two yrs, last month my blood pressure was high , so they increase my perindopril to 8 mg with amlodipine, but as I observe although my bp settled a bit but still diastolic of above 90, went to Gp , prescribed me to start bendroflumethiazide 2.5 mg with 8 mg perindopril ,then stop my amlodipine , actually I was prescribed this bendroflumethiazide alone, with no other combination of 5 yrs ago, they only stop it because my potassium was below normal, so it it ok to take this perindopril with bendroflumethiazide? I'm worried coz of my potassium again, thanks...