You ask some excellent questions. It is possible that you did compress a nerve and that was responsible for your initial symptoms. However, it would definitely be unexpected for this to last for several days. Numbness
and tingling does suggest that something is going on with your nervous system--the question is whether or not it is a central process (i.e. from the brain/spinal cord) or a peripheral process (from the nerves in the rest of your body). In order to figure this out--and to protect your longterm health--you should definitely see a physician right away for a thorough exam. It will be very important to determine exactly what part(s) of your leg are having sensory problems as well as whether or not you show any evidence of other neurologic abnormalities on exam. From what you describe, it is certainly possible that you have a bulging disc or other compression in your lower back that is affecting the nerves that leave the spinal cord and supply sensation in your leg. You could also have what is called a 'peripheral neuropathy
' where nerves in certain parts of the body stop working properly. To determine what is going on you will definitely need a physical exam/history, quite possibly some imaging of your spine, and maybe some tests of nerve conduction.