What Causes Discomfort In Bladder And Sudden Urge To Urinate?

I have a history of kidney stones. I developed bladder discomfort about a month ago. Could be a stone but feels different than the others. Sometimes it feels like a tugging feeling and sometimes makes me feel like I need to urinate. Years ago I had a hysterectomy where my bladder had adhered to my uterus with endometriosis. I am wondering if something similar may have happened, or I may have another stone or something else entirely. Suggestions?