I thought Uti?

So I’ve been having a burning sensation when I pee and quite a few on off cramps. I went to the doctors today as now the burning is there constant. She tested for uti and said I don’t show any signs of infection 🤷🏻‍♀️ but there way traces of blood. She didn’t give me any antibiotics as she wants to get more in-depth tests done and because she said it could be pregnancy? Has anyone else experienced this as an early pregnancy sign?