Uti symptom help

I didn’t get any answers last time I posted. I have been taking antibiotics for a UTI but my culture came back negative for infection. It feels like I have a UTI and I don’t understand what else it could be. I called my OB this morning and they just told me that it could be pressure from the baby and to finish the antibiotics. I thought they might want to test for other things, although idk what else it would be. I’m only 26 weeks and never felt this with my first baby. Should I get a second opinion? 😕