Burning and urgency

So I am now almost 15 weeks pregnant. I have had three uti tests done all coming back negative. After I pee I feel like I’m burning down there, no burning when I pee and also feel like I can’t sleep at all because I feel like I can feel every droplet of pee in me and can’t get it out. Idk what to do anymore and what to ask my doctor on my appointment at Friday. I’m in a ton of discomfort and need relief.