with your symptoms most likely cause is stone in the urinary tract
mostly in the left lower ureter
or bladder. That explains all your symptoms of blood in urine, pain in the abdomen and the frequent urge to pass urine with little urine coming out. You need urine examination, ultrasound
of your abdomen and x-ray of the abdomen. Please consult a urologist
Drink adequate water but if your stone is obstructed, you need medical attention as early as possible.