Your symptoms are suggestive of sciatica. Sciatica is a symptom not a diagnosis It is a non-specific term commonly used to describe symptoms of pain radiating downward from the buttock over the posterior or lateral side of the lower limb. It is caused by certain positions are usually associated with continually holding a poor posture either at home or at work.
Imaging methods such as MR Neurography may help diagnosis and treatment of sciatica. You can take OTC pain killers like brufen,do some stretching exercises and yoga and maintain a correct upright posture while sitting.
Severe cases may require surgery.
Other possibilities are dehydration or low amounts of potassium, sodium, calcium, or magnesium in the blood, muscle fatigue or strain from overuse, too much exercise, or holding a muscle in the same position for a long time, tendonitis, claudication, osteomyelitis,osteoarthritis, Benign tumors or cysts of the femur or tibia and osteosarcoma.
Pls consult your orthopaedician if the symptoms persist or become severe.Other causes have to be probed then.
Hope it helps.Take care and pls do keep me posted on how you are doing