I am 35 weeks pregnant. i am having uti symptoms such as frequent urination, lower back pain, & foul odor smelling urine. but doctor says i don't have a uti. what could it be?

Cystitis: The uterus is sitting right on top of the bladder, compressingit and not allowing it to fill correctly. These symptoms are not uncommon.

?Nitrite negative: Possibly dr. Performed a "dipstick" test on your urine. Nitrite reagent on strip changes color for most, but by no means all, bacteria. Symptoms strongly suggest a uti. Urine culture is much more relaible, also urine microscopy & gram stain of urinary sediment. Your dr. Could safely put you on an antibiotic once urine sample has been provided, even before result of culture is returned. Good luck.