No, you don't, but it would be ideal. FPS is the measure of frames that your graphics card can render every second, while Hz is the measure of frames that your monitor can display every second. When the two are not in sink, be it the frame rate is higher than the refresh rate or vice-versa, you'll get what's known as screen tearing. Screen tearing occurs because either two frames are drawn so quickly in succession that both are cut in half and displayed at the same time or a monitor is displaying too fast for the graphics card so it ends up displaying some frames more than once, and other frames only once, causing a jaggy or unsmooth game.
Optimally, the best way to experience smooth gameplay is to make sure the two match one another, or at least ensure that they're consistent multiples of one another. V-Sync locks your frame rate to the monitor's refresh rate so tearing is removed, which is great, but it causes input lag and it doesn't work efficiently if your frame rate is less than your refresh rate. If your frame rate is less than your refresh rate, what apparently happens is that your frame rate sometimes automatically drops to half your refresh rate so as to make sure every frame is displayed twice. I say apparently because I don't really experience that when I game and my fps falls under my refresh rate with V-Sync on.
Ignoring that, in your case if your monitor is 144 Hz and your frame rate is about 70, then you're probably getting a fairly consistent experience, as for the most part, every frame is displayed twice on your monitor, with 4 out of every 144 frames being displayed once. So your eye probably doesn't pick up on those 4 frame being displayed once compared to the 70 other frames being displayed twice, meaning that, assuming you're consistently at 70 fps, what you're viewing is consistent and smooth. Now, of course there'd be amazing advantages to having your frame rate be higher, that is, you'd visibly see more frames per second and have an even smoother (though not necessarily more consistent) experience.