welcome to HCM
Yes due to yoga
by the twisting any or uneven pressure effect could be the cause of displacement of disc. Yes there might be loosen and when it give pressure to spinal nerve
you feel pain. As the unset is sudden and just after a few days of yoga postural movement so those chances are maximum. But if it would have been a long days gradual origin then we should think for others factors like osteoporosis
or any any spinal growth etc. The exact cause can be found out by CT Scan
of whole spine.