Chances of false positive

Hey, I've had the IUD for a little over 9 months now. I went to the doctor for a UTI where they ran a pregnancy test and it came back positive. They did another and it came back negative. I am going to go see my obgyn to triple check but now I'm having watery discharge with bloody streaks. I dont feel pregnant? I dont feel any different? I honestly feel like this whole thing is a fluke but it has gotten into my head a little bit. Has anyone had this happen? It was a fast pace clinic so they wrote it off as negative but it has me a little nervous for sure!