I can understand your fears. Once in a while an individual may have loss of sensation in leg or a feeling of one leg being dragged due to exposure to cold at night, uneven bed, wrong posture etc. It could also be a sign of mini-stroke. So, please consult your doctor regarding this. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.