Freq urination, abdominal pain, blood normal, urine normal, pelvic exam normal, ultrasound normal, what could be wrong?

Urinary frequency: Glad you had the urine test and pelvic exam first! So thinking about what other organs are in that region, the large or small intestines are the next thing to consider. IBS can cause abd pain and urinary frequency but don't jump to the diagnosis yet. Interstitial cystitis can do this too. Consider visiting a gastroenterologist and possibly a urologist if the problem continues.