Hello, and I hope I can help you today.
If what you say is true that the blood is only in your urine and not coming from the vagina, then is really cannot be something that is related to the baby.
The fact that there are no bacteria in your urine makes your symptoms most consistent with a bladder or
kidney stone. Intermittent pain may mean you are passing small pieces of stones at irregular intervals. They can cause heavy bladder bleeding and can make you feel very sick.
I know that you are concerned that your symptoms could be caused by something else, but I agree with the nurse's recommendation to get an
ultrasound of your kidney. If you feel sick enough or are in too much pain, or if you develop a
fever, you should go to the emergency room for evaluation. It is most likely the baby is fine, but you may not be able to wait to get your culture results from your doctor.
I hope I was able to answer your question and that my advice was helpful.
Best wishes, and I hope you feel better, Dr. Brown