Hi
Welcome to the forum!
Your medical history mentions a bad stench in urine. Generally bad odor is due to infection, mainly by E coli. This can be diagnosed by urine culture. This can also cause cystitis (urinary bladder infection) and lower abdominal discomfort.
If the urine smell is that of rotten eggs, then this comes from sulfites in the diet. If you are sensitive to them, it can cause abdominal discomfort as you are having.
Another possibility is a STD. With a history of unprotected sex, this should be ruled out. Please discuss with your gynecologist as confirmed diagnosis cannot be given on net. Hope this helps. Take care!