lower abdominal pains

i have lower abdominal pains. i have been to doctors a few times and she gave me tramadols and diclofenac and cocodamol at different times. but it hasnt helped. i have had this pain for 3 weeks now. doctor also referred me to go to hospital at the gynacology ward. and they checked me internally, took swab tests, urine tests, internal and external ultrasound scans. but they found everything normal. all tests negative. i am really fed up of this please can anyone help me??