Is 127/84 bp ok?

One time not enough: BP can change up and down. Those numbers alone are ok but more important is to check it daily for two weeks at least and se what happens.

Prehypertension.: BP numbers in this range would suggest prehypertension, a harbinger of the eventual development of true high blood pressure, especially if such runs in your family. Concentrate on proper diet, regular exercise and salt restriction. If you smoke, stop. If you're stressed, relax. You can lower your BP numbers naturally if you work at it.