Is it recommended when sleeping on my side to have a pillow between your legs/knees, why do i feel so uncomfortable?

Perhaps side: Sleeping just isn't optimal for you. Sleeping on your back can aid the head ; spine to maintain a neutral position. It is consider the optimal sleep position for most people. If you do wish to sleep on your side - pillows are designed for placement between legs. Additionally, when sleeping on your side a thick pillow can help to maintain your neck ; head in a neutral position.