Stop squatting till the pain goes away. I had mild pain in my back for a couple months and never thought much of it, some days were better than others, but I felt shitty squatting most of the time. One week during this period I decided to try to match my 10 rep max (using 405), even though that day my back felt shitty. I completed the set without any sudden failure, however a few hours later I developed bad sciatic pain, lost the function of my calf muscle and half my foot went numb. I had 6 weeks of bad pain, couldn't sit or stand or even lie in bed without pain. 4 months later I am still having nerve problems, however my calf seems to be slowly progressing and I have been pain free for a while.
Moral of the story - don't squat if it is causing pain. Take the time off and fix your problem.