What Does Kidney Stone Like Discharge In Urine Of A Child Indicate?

My 6 year old daughter the other passed what at first I thought looked like a red kidney stone. Upon further exam it was soft and not stone like more like a blood clot. She said it hurt when she passed it and it sometimes when she urinates it hurts. She doesn t see blood when she wipes and has not had any other symptoms. Could this still be a UTI? I ve never seen clots pass like that it was small but concerning. I don t want to rush to the doctor if it s nothing because she does like to make up stories at times. But i did see this one. She says she saw another one today at school. I m just not sure what to do at this point.