Missy - i had an asymptomatic UTI early in pregnancy (i think about 18 weeks) and the culture didn't grow as what happened with you. i had white blood cells in my urine and was actually getting pain in around both my kidney and my liver

i have done a lot of study on microbiology and i don't doubt that i had an infection even though the specimen culture didn't grow - basically, when you're pregnant, you have heaps more cervical mucus and that mucus can actually prevent the bacteria surviving in the wee sample to get to the lab! if you're still having pain, get it checked for sure - it may be that you HAD a UTI that has been treated by the Ab's and the pain you're now feeling cos simply be related to the way your baby is laying (mine appears to have moved posterior today and OMG it hurts!)

keep up the water (lots of), use the cranberry juice (with no sugar added i think you need) or have some ural - i dont find it gross (i use the normal one, not cranberry one) - and once it's all cleared up, take the ural every couple of days to stay on top of keeping your kidneys flushed!

hope you get some relief soon