What is blood after urinating and back pain? as well as pelvic pain?

There are many: Potential causes. You might have kidney stones. It might reflect a urinary tract infection or a kidney infection. In these situations you wil have fever, burning when you urinate commonly. Your blood work if you have a kidney infection or a bad urine infection will reveal an elevated white count. It might otherwise reflect processes related to your uterus as well such as fibroid... See your md!

Kidney stone?: Blood in the urine and back pain (usually in the flank areas where the kidneys are ) may be a stone. They cause an intense referred pain in the pelvic region as the stones stretch and pass through the tubes from the kidneys on the way to the bladder (ureters). That's what you'd symptoms sound most consistent with.