What Causes Pelvic Pain With Swelling?

Hi Doctor, 2 days ago I started feeling strong pain in my pelvic and was taken by emergency, they did urine and blood test but everything was clear. Pain didn't get better and my pelvic is swallown still. Today I went to different doctor, she without taking my urine test said that I am having a UTI and gave me some antibiotics, I don't know what to do?