ants in legs from lying on my back?

Marie

I end up sleeping on my back very often and I haven't really been forcing myself to the side since it's still early in pregnancy (now 12w2d)

But I've recently woken up with no blood circulation in my leg... the same feeling as when you've been sleeping on your arm and it goes dead...?

Is my uterus heavy enough already to cause squishing of the veins when lying on our back?