I am sorry about your history with ovarian cancer, and I think that your doctors should have been more diligent in pursuing the issue if you were having symptoms. However, I don't think it's helpful on a hypochondriac forum to focus on extremely rare occurrences. I also don't think it's helpful to assume that the doctor's diagnostic methods are not accurate, because that's another rare occurrence. It's a medical fact that the main risk factor for almost all forms of cancer is age.
That said, I agree that any unusual and worrying symptoms do need to be evaluated by a doctor, and that, if you genuinely feel he/she has gotten wrong, you need to seek a second opinion. If I were experiencing anal bleeding that lasted for a few days, I would go and see the doctor, and get whatever tests were considered necessary.