Worried

I am 5 weeks pregnant and I recently found out I have a uti. Well the test came out negative but because of the symptoms the dr thinks it’s a uti. I’ve had them before and it feels just the same. Except this time I’m taking macrobid. I started taking it Wednesday night. I told the nurse Friday I don’t feel any better. She said keep taking it and if I don’t feel better after I finish it to come back. I’ll be out of pills by Tuesday. Today I started feeling really nauseous. When that happends I don’t eat or drink anything. I sipped on 7 up and it helped the nausea. I just got up off the couch and went to go pee. Soon as I finished I had extreme cramps. I’m starting to worry that something is going to happen. I’m not sure what to do. I’ve heard that cramping is common in early pregnancy but scared this is still a uti problem. What should I do?