I have a big pelvis compared to the rest of me (which is of course good in the grand scheme of things).
Unfortunately, even now I'm carrying 33 weeks, the very sides of my hips aren't excessively padded unlike the rest of me. My bump and baby are big and heavy, just all out front. So I sleep on my side as they tell me to: and by the morning the corner of the pelvis on the bed, no matter what I use, feels squashed and like it has been pressed hard all night by the weight of the rest of my body (being the most stcky-out bit). :( It's not SPD or anything like that: purely the weight of my body going mostly through my massive hips pelvis onto the bed. Once I've been up a while it fades completely.
I have tried many pillows/cushions. Any other ideas? I seem to be OK from about 10pm-4am, then wake up and it's 'ouch'!