i would say if there is a smell and colour then it could definately be an infection of some kind. on the other hand i have been having a similar issue (minus the odour though) had a swab done and it was normal. so best bet is to see what your doctor says. btw, you can have thrush without any itching too.

i doubt that it would be your waters though, cause they would be clear (or greenish if the bub has been under stress) and the consistency would be more watery than the thickness of discharge.

you dont have long to go, best of luck! :-)