E, it's not unusual to got bits of blood in the catheter tube and bag , quite often they are bits of dissolved scab. An odd couple of clots should be okay,but I am not your doctor, if they get worse or you get any bright red blood or you are concerned contact your medical team.
I was told rosé wine colour urine in the bag should be okay Red wine colour should be investigated.
Have you been overdoing things,that is often the cause of blood in the bag.
Thanks Chris