UTI or ???

I’m 2 days away from AF, first month TTC and BFN as of today. I have annoying lower back pain and I’ve had dull lower abdomen cramping since Sunday. I have a doctor’s appointment tomorrow to check if I have a UTI, and in the meantime I’ve taken AZO and drank plenty of water. It’s so interesting though; I have no more urge to pee than normal, no stinging, no cloudiness, and no smell. Anyone else have any ideas on what it could be? Or just the symptoms I have and it still being a UTI? Also, AZO dried me right out!! Not sure if anyone’s had this side effect? Zero discharge. This whole thing totally convinced me I was going to get a BFP this month. I’ve never had cramps that felt like this. TIA for the opinions. Anything helps ease my anxiety. 🙃