Pain in the leg that originates with a disc problem or a stenosis issue usually are in one leg only. There are exceptions to this, particularly when there is some instability, which is why I asked about the flexion/extension x-ray. This test most clearly and inexpensively shows a condition called spondylolisthesis, which is when one vertebra slips over the top of the adjacent one.
Another situation is when a disc bulges not to the left or to the right side, but in the middle region. Then the pain can effect both legs, one or the other...and can kind of come and go, back and forth.
You might want to look online for a "dermatome map." You may find it interesting to see if your pain corresponds to a particular pattern. As you probably know, the spinal nerves innervate various parts of the body, with cervical spinal nerves covering the upper limbs, and lumbar mainly covering the lower limbs. If you go to the doctor and tell her you big toe is numb, she will know to begin her search for something is compressing the L4 nerve...there's nothing magical about it. The nerves run in a particular pattern that sensitize a particular area. When a nerve is compressed in the spine, pain can be felt anywhere along the nerve's pathway.
If you do get a MRI, be sure to ask for a copy of the disc and the radiology report. It is a good idea to get into the habit of keeping a file with copies of your tests, MRIs, etc. Hopefully, this pain will be a one-shot thing...but if you end up with ongoing issues, it is very handy to have these records on hand without having to go back to the original source and wait and wait to get copies. Plus, then you can come back here and tell us in detail what the MRI found!