Im terified

My partner had tests in November. Blood tests  showed the top end ca125 in the blood. She had a abdominal ulrtrasound and and vaginal ultrasound ( both came back clear).  Her coloscopy found 14 polys which all tested negatove and where left in?

Since then the pain hasnt gone. The bowels habits have gone all over the placese has been tested for having blood` in her bowel movements and now has to go back.

Her father died of bowel cancer which was missed in hospital and we are frightened the same has happened. 

Can all these test miss it?