Major back pain gone. foot and lower leg now numb. what is danger of going untreated. can't see specialist for 3 weeks. no mri no pt until diagnosed?

Stress urgency: urgent evaluation is imperative for such changes. I would call the office in the morning and request for a much sooner appointment considering you are having dynamic neurological changes. You could also go in to see your primary care physician to see if there are any other red flags that show up on a complete neurological physical examination of you in person. Don't sit on it.