Girls, please tell me something. My back (lower back) started hurting,…

Girls, please tell me something. My back (lower back) started hurting, it used to hurt only when I walked and sat for a long time. But a couple of days ago I woke up and can't bend back or forward. No discharge, just pain in my lower back. To blow me doesn't remember, I take care of myself. To the doctor already on 25th. Has anyone had this? What could it be?