Been peeing small blood clots, white rock looking things, and just now a black speck size of a grain of rice? what could it be? i had ultrasounds earlier this year showing me clear when i have chronic pelvic pain?

You need to see a urologist. You will require urine testing and more advanced imaging of the urinary system.

Blood in uriine is common with kidney or urinary bladder stones.Many ultrasounds miss kidney stones. Did you also have an U/S of the urinary bladder where there could be stones? Did you strain.& catch any specimens so the lab can examine them? I recommend consulting a urologist to order appropriate testing to clarify the problem and advise you.