Lower Back Discomfort Progressing

Patient: I’m a fairly active 21 year old. As far back as last year, right around November, I began experiencing discomfort in my lower back(more so on the sides, right above my tail bone.) It wasn’t attention grabbing, nor was it something I deemed serious. But as time went on, the discomfort began to radiate from my lower back down to my left leg, specifically right above the knee cap. At times, some minor abdominal stomach pain. But nonetheless to serious. But as of today, it has been coming of as RLS. Can’t sleep peacefully at night. Lower back feels troubled and my legs need to move. Or I need to move them. I never injured my back. Neither have I been misdirecting my body. But its becoming more constant. Is this a pinched nerve, DVT, or something more or less along the lines of immobility sensation?