I developed really young. Had boobs and period at age 9......And boobs seem to have been growing ever since. I am around a 42 DD. Anyways I find that when I sleep I am constantly moving all over the place. I start out on my back.....sleep on my sides.....and if I am cold....I end up sleeping on my tummy. I think it depends on if you like sleeping with a big fluffy pillow. My boobs feel like I am sleeping on two big fluffy pillows.....Sometimes they feel like they become one with the big fluffly pillow. The only time I ever have any problems is when I have some slight back pain the next day......and I need to do my back stretches to get my back ......back in line. Sometimes it is the only way I know that I slept on my back some the night before.

Anyways......I tend to try to avoid sleeping on my back......just because I don't like back pain the next day.......sciatica is not a lot of fun.