This is probably no good to you now anyway, but I got a UTI when I did LL a while back, and it was only in week 2.
I went to doc, got antibiotics, and stayed on LL.
According to doc the reason that I got it in first place was cos I wasn't drinking enough water to dilute the uric acid. He recommended that I stop LL because uric acid is a by product of diet, but I said no, so he told me that I needed to drink loads more water to avoid it happening again. I drank loads more, and it never happened again (on that diet anyway, have had it since after a night on the wine!!).
I cant remember where the uric acid was (he did say bladder or kidney, can't remember now) but that was the advice.
But if your CDC tells you to stop, you probably better do what s/he says!