after surgery symptoms bright red blood

i had ovaries and tubes removed 5 days ago and tonight there was bright red blood (clot maybe size of small fingernail and some streaks ) what would cause this and what should i do - i did drive a short distance today but i am having no pain and movement is good - i am 52 - they did a fair amount of work during the surgery as my bowels had adhered to the pelvic wall and other things.