Lower back pain from laying down too much. should i be concerned?

Back pain: First why are you laying down so much? Is there a medical condition that prevents you from being active. Too much inactivity can lead to atropy of the muscles of the back which can cause pain.

Not unless you are: Obviously laying down is a normal thing to do. But if pain bothers you enough consider evaluation for your back pain. There may be many reasons you could be having pains.