Is It Normal For My Pulse To Be Lower And Diastolic BP To Be Higher During Some Blood Pressure Readings?

Hi, my question is that about 1 in 5 times i check my blood pressure, that one reading my pulse will be about 40bpm lower and along with this my diastolic bp will be 15-25mmhg higher than usual . does this sound normal??? Its a fairly notable change and the low pulse/high dbp always seem to go together....?