burning pee helpp its not a uti!

ok so i went to the doctors today because i was certain i had a uti bc of bad constant burning when i pee and bad smell soo i go in and they say i had nothing in my urine and they are going to culture it?!? i am so scared because this does not feel right and i am so scared this could afect my baby , has this ever happed to you? if so what was it or any suggestions to what it might be? i would really apreciate the info now i have to wait until next week