Yes, it could be mis-calibrated; I wouldn't expect the needle to go past the bottom-most marks. The marks about 1/3 from the bottom are a rough guide as to the highest you would ever want to set the trim while under way. But, even those marks are too high on my boat; my optimum trim is about 1/3 of the way down from those marks, relative to the bottom of the scale - and I only trim that high while in the upper speed range.
In case you don't know... finding your optimum trim setting is easiest when you have calm water and room to run straight. You want to make very small adjustments to the trim and carefully watch speed and RPM's. As you trim up from fully down, you'll see speed increase without any additional throttle; as you continue trimming up (again, just a little at a time), you'll find a point at which speed begins to drop again. At that point, you just went past your optimum setting at that speed.
In time you'll get to where you just go by sound & feel, and won't use the gauge much anyway. That doesn't mean it shouldn't be calibrated correctly.
Welcome to the board.