You could be dehydrated? Try to drink more water :)
Have you taken your glucose test? Gestational diabetes can change smell and appearance too.
Go visit your ob or midwife and ask them what they think,they will most likely do you a sample and maybe a swab (depending) and see what's going on, I got that at one point and I had strep B and UTIs and preeclampsya but as far as I know it was not related to the latter. Best to be safe and have it checked. Congratulations by the way,boy or girl? I'm 27 weeks with a boy,I already have a 15 month old girl also :-)
Thanks everyone its a boy