I have an Omron monitor also. One time, my BP suddenly shot up to the stratosphere, something like 210/160. But I felt fine. Scared to death, I grabbed the monitor and headed immediately for the doctor's office. He checked nmy BP with his own machine; it was perfectly normal. But my Omron machine does keep a "memory" of the past three readings, so he could see that it was real. Suddenly he saw what the problem was: a kink in the machine's cable line. He straightened it out, and bingo, my BP went right back down to normal.
So beware of home BP monitors!