We will break it down into a simple shape to make it easier for us to visualize.
From the front, the silhouette might resemble a butterfly.
From profile, the silhouette is a little harder to relate to, perhaps an unusual looking claw or hornbill.
Next we're thinking in 3D, try to see the pelvis as a bucket or cork shape, squashed a little at the front and back. There's a wedge shape removed from the front, leaving a shelf.
Use a basic bucket shape when placing the pelvis on your figure drawing. You can also try simple oval shapes, or a box, whatever works for you. Be sure to draw the form tilting forwards.
We'll explore the pelvis in greater detail in a later tutorial.