I was reading your post and quite distressed about your situation and the dismissiveness. I would contact another imaging center or ob/gyn and ask if you can get a second opinion, or if you live near a large cancer center or teaching hospital that might be even better.
As for it being in you record that you had concerns, I believe that might be a double edged sword. Yes, you want to know you have the right to be concerned, on the other the comments might end up labeling you as “that patient”. I can’t say what might be better.
All I can say is you know your body better than anyone else possibly can, if you believe there is a problem keep seeking until you are satisfied.
Do you have the ability to travel to a large center with your records?