I am experiencing no menstrual periods and abnormal vaginal bleeding (quality: contains blood clots) only when urinating blood clots come out.

Possible UTI: Are you having any other urinary symptoms? Frequency, urgency? It is possible your symptoms may be related to urinary tract infection, in which case, you would need antibiotics to clear it. Would recommend you contact your doctors office for further recommendations.

UTI,Cystitis : How long have you had this, do you have any pain when passing clots, is there also burning in urination, frequency, urgency, fever, back pain? It could be hemorrhagic cystitis- where bladder wall is inflammed and bleeding, a UTI or a bleeding mass/tumor or blood vessel. You will surely need a simple urine study but may need a urologist to do cystoscopy