Hello,
When the blood in the urine is at the beginning of urination, it most likely comes from the urethra, (the tube from the bladder to the outside). Blood throughout urination is most likely from the bladder or kidneys or ureters (the tubes connecting the kidneys and the bladder).
Diagnostic tests that may be performed include Urinalysis, Urine culture, X-rays of the kidneys, Cystoscopy, IVP, Abdominal ultrasound and CT scan of the abdomen.
I hope it helps. Take care and regards.
The Bleeding and pain stop after half a day. Could it be a internal injury?