UTI mystery symptoms, ideas?

warning: this is a little graphic! (female, 20y.o.)
I have some kind of weird UTI(urinary tract infection) like symptoms, such as pain in urethra, weak stream, constant urge to pee, and even vaginal pain. here's some info:
I had a bad uti/bladder infection last July that was treated and cured, uti tests have came back negative everytime since then(i've had a total of 7 since october) At first, in oct., my doctor thought i had a slight uti still and gave me more antibiotics- didn't work. then, i had a IVP scan done of my bladder and kidneys and flushed with iodine and a Ultrasound of my bladder and vaginal area- my right kidney was slightly enlarged but still no answer. So they put me on overactive bladder med- which caused my bladder to cramp bad and made it harder to relieve myself. I've been pregnant since late February, and my OB/GYN said i might have scarring, just drink lots of water(doesn't help). Any ideas to what else could be manifesting itself like this?

forgot to mention, i've had 2 pap smears, one in Oct. and then in late April '07- both negative for everything.

get checked for Trichomoniasis (Trichomonas) they invade the urinary tract as well as the reproductive tract.

thhat would be my first guess. they often dont test for this particular ailment, but it is very common.

just go to your doctor and ask them to check for this.

maybe u need to c a urologist ( one who specializes in urinary and urinary tract problems)

I sort of went through a similar experience. I had a UTI and was put on two different antibiotics (bactirm and Cipro). Bactrim didn't work so they put me on Cipro which worked better but i still felt the symptoms of pain in the uretha, cramps, constant urge to urinate but this time my urine culture came back negative. I finally went to my GYN and was diagnosed with BV which i believe came from the use of antibiotics that killed the good bacteria in my vagina. I would recommend you go to your GYN or clinic and have them take a swab of your vagina more than likely you have a vagina infection that feels like its still a UTI. I also recommend you take probiotics such as Kefir or yogurt to bring back the good bacteria down there as well as taking one capsule a day of lactobacillus to balance the flora in your body. Good Luck!