Unfortunately we have to be our own advocates. You know your body and must insist on the ultrasound. Good luck and keep us posted.
I think that you should get an ultrasound done but also, i wanted to mention that I had the same kind of pain around April last year, it would hit me about every two weeks and it felt like labor and would last about 24 hours. It was so intense, the pain. Finally, in June I went to the ER and they did a CT which showed my appendix was inflamed. Now, it hurt all over, not just on my right side where my appendix is. So they scheduled me for that surgery and when they pulled out my appendix, it didn't look as bad as my white cell blood count showed, so they looked around. It turned out that I had a foot long section of my intestine that was scarred and twisted. So I had an additional surgery to have that removed. They said I had chronic appendicitis and that was the pain every 2 weeks. Just some other thoughts for you if it turns out not to be gynocologically related. You might want to mention this too. Let us know!