You are lucky..
If you are on the tall side, the uterus
has more room to "elongate" upward rather than bulging outward, thus the appearance of smaller pregnant belly.
Shorter ladies often show bigger pregnant bellies. Also, the curvature of lowback can influence the show of your front belly. You feel well n baby is growing normally, that is all that matters..Just tell people you carry it well. Congrats. Good luck.