Ghost pees

I am 17 years old, on the IUD, and have been sexually active since I was 14. Even though I've had a somewhat rich sexual history (now it's been long term monogamous) I always make an extreme effort to stay up on my sexual health (take pregnancy tests, get std tested regularly, etc) and talk openly to my doctor. Ever since the day I lost my virginity, all these years later, I have felt like I'm on this never ending UTI. I go to the doctor again and again and again but I never have a UTI and all my lab results come back normal. I always feel like I have a full bladder, I urinate quite frequently, and although I wouldn't call it painful, I consider it to be maddening and extremely uncomfortable. I'm going to go visit my GYN and try to get some clarity once again, but my hopes aren't high. Someone please help.