I have blood in my urine and pain under my belly button. i had a hysterectomy 5 years ago, so what could this be?

A few things: It is abnormal, but it could be as simple as a bladder infection (UTI). Those are usually characterized by a sensation of burning about midway through urination or by a sensation of having to pee more often than you really need to. If not a simple UTI, could be a kidney stone, other kidney issue, or noninfectious (not bacteria) bladder issue that would need further investigation.