Kidney infection

I am going to the Dr today anyways, but just looking for insight. How did you know you had a kidney infection? I've had a uti that is just not budging for a couple weeks now. Dr originally prescribed cephalexin but because of the result of my labs, changed the prescription to macrobid a few days before my cephalexin rx was complete. Now I've just finished the macrobid (7 day treatment) and im still having symptoms and having some lower back/abdominal pain. It is literally the worst, and it just started up this morning. Feeling like I'm never going to not have an infection again 😩 i miss not having to pee every 5 seconds and having sex 😭😫