After sex, I have pain in my lower abdomen, frequent urination, painful urination, and blood in my urine. I have to urinate constantly, very uncomfortable. So doctor, can you tell me if pain in my lower abdomen and frequent urination after sex are serious? Thank you doctor.

Hi doctor! I often have pain in my left waist and left lower abdomen, and I often get angry when I need to urinate. Currently, the urination and all activities are still normal, no night urination, normal urine. This phenomenon has been repeated for several years. I have been to the doctor, ultrasound, urine tests all have normal results. So the doctor asked me: "What is the symptom of the left lumbar pain, the lower abdomen is the symptom?" What else do you need to check? Looking forward to the doctor's advice and answers! I sincerely thank!