Arms hurt like hell when I sleep?!

So I sleep on my sides with my arm on that side under my pillow I always have. My arm always hurts and I have to roll on my other side until that arm hurts then repeat all night. Now that I am pregnant it's a million times worse. Especially last night. I actually dreamt my arm was being crushed and I was crying and the pain was very intense. I woke up and my arm was in that same amount of pain and I had to roll over and it finally stopped hurting after 5+ minutes. Is it a calcium problem? Is anyone else experiencing or experienced this? I don't drink milk I can't stand milk or I would. Even as early as third grade I didn't drink milk and since then. So I think that has to do with it like the baby is sucking the little calcium I have in my body out of me. I'm afraid of getting brittle bone.