35 weeks

I took a 2 hour nap this morning after sending the kids to school . woke up to knocking on the front door so I rush to get up only to fall back down my left leg was asleep and I was laying on my right side i hit my ribs and the top of my tummy on my night stand baby is moving and small cramping no bleeding. How can my left leg be asleep if I'm laying on my right side?