WILD - limbs falling asleep?

[Puffin]

I decided, last night, to try the regular variation of WILD described in the forum's tutorial, even though I really hate getting SP. I sleep on my stomach with my arms at my sides. After only around 10 minutes of lying still and breathing normally, my hands and fingers began to fall asleep, as if they were getting numb, and it was extremely uncomfortable. I'm not sure whether this was the onset SP or not. It's easy for me to stay mentally relaxed, but the numb feeling in my limbs, especially my fingers and hands, is daunting. I want to try again tonight, but I'm not sure how to deal with it. Tips or suggestions? If it isn't SP, what can prevent me from numbing up? If nothing works, I will try DEILDing. Thanks, Demara