So i read online that the best way is sleeping on your left side with pillow between the knees. Wgich wouldnt be a problem but over night my left arm gets really tired and my shoulder is killing me. So i end up on my back wich i researched online yet again and some info said that its not the safest way to go because from my understanding theres a major vein in ur back and the baby can squish it which can cause complication for you and/or baby. Is that true? Im much more comfy on my back and ive been trying really hard to sleep on my side, now im just freaked out. Has anyone else slept on the back during the pregnancy? Im just about 12 weeks now.