Hi Sri! I actually had a UTI last cycle (remember?) and it was also in the 2WW. My doctor treated me right away with an antibiotic that was supposed to be safe for pregnancy...so if I was pregnant, i would have been OK. If I were you, I would call and ask your doctor what he/she thinks...and whether they want you to start any medication or not, you could at least go and have a urine sample done so that they can confirm that it is a UTI.
Personally, I was so uncomfortable, I had to go in right away, but I know different people have different symptoms with UTIs. While you're waiting, make sure you drink lots of water to flush as much of the bacteria out as possible, and maybe drink some cranberry juice too!
Hope you feel better soon!