What Causes Abdominal Pain And White Tissue Pieces In Urine?

I had a uti that went away but seems to have returned. I believe it is back because I have the stomach pain and white pieces of tissue in my pee. Does it sound like a uti or something more? I didn t check my pee before when i had the uti. Only noticed it now as I peed in a cup to test if ovulating. That is when I saw the chucks. Please let me know your thoughts. Thank you very much.