Blood found in urine. Now have to go for kidney ultrasoun

Hi. I am 41. I had a blood clot in my leg in April of this year. Treated with apixaban. As part of this treatment I needed to have a urine sample taken. It showed trace blood. I have since repeated these samples, even after finishing the apixaban and still trace blood. I had a flexible cystoscopy today for my bladder and it showed normal. So now, I am awaiting another urine sample check for malignant cells and an ultrasound on my kidneys as the consultant thinks this is where the problem must be as not in my bladder. I'm going in on Thursday for this. So  very very frightened.