Hello, allow me to jump in here. Do you have an online account that will allow you to message your nephrologist? I have access to “My Chart” and all of my doctors can share information. Most doctors now have online access. Maybe you can send her/him an email and ask if you need an early appointment. I had a UTI and was treated with Bactrim. It threw my labs out of wack. I understand how upsetting it can be to get a negative test result. I hope this is helpful.