Is it always that the middle part of the body is at or above the base of the penis? Because my middle part of the body is 1.5 inches below the base of my penis. I'm in Tanner stage 4.1. My father's height is 5'6 and mother's is 5'0. Mmy present height is 5'5.
In childhood, the middle of body is around your navel. Part of this is due to the fact that a child's head is proportionally larger for the size of his body. When you have your growth spurt in stage 3, your legs and arms grow rapidly and this shifts the midpoint of the body downwards to below the penis. During stage 4, the trunk of your body does most of the growing and this brings the midpoint back up to around the base of the penis.
In your case, you've just recently finished your heaviest growth spurt, so your midpoint is below your penis. During the next two years your upper body will grow and your midpoint will shift to be around the base of your penis.