Severe pain

I went to the hospital yesterday for severe lower back pain on my right side and a sharp stinging pain in my vagina when I’m finishing peeing. No UTI as there was no bacteria present. They think it’s a kidney stone but couldn’t confirm it other than an elevated white blood cell count and blood in my urine. I eventually got discharged because they were only giving me IVs and I’d be more comfortable at home with a heating pad. I’m still in severe pain today and don’t know what to do. I’m drinking a lot of water. I don’t want to go back to the hospital to just lay there. Has anyone had kidney stones before? How long did they take to pass? I’m 29 weeks pregnant