Suggest Treatment For Stabbing Pain In The Upper Abdominal Area

I have a few concerns at the moment, I went to headspace today and couldnt get a scan (STI) done as ive been bleeding unusually for the past few days. I m not sure what the bleeding in caused by as im on the pill and have skipped my period, although the bleeding is quite heavy. Its also very likely that i have chlamydia.. because my sexual partner has just been diagnosed. My other concern is nearly unbearable pain in my upper abdominals; it has happened 3 times now, like a stabbing pain but i thought it was caused by having neurofen without eating as both times the pain came was after i had it.. but the pain has just come back and i haven t taken any