I cough up blood but have had a CT scan and bronchoscopy that all came back normal?

I am a 33 year old female. I cough up blood but have had a CT scan and bronchoscopy that all came back normal except for a cavitary lesion that was 2 cm. The doctor is watching it, and coughing up blood has decreased. However, Friday afternoon, the right side of my chest started hurting when I breathed in deeply or coughed. It’s still hurting, and is worse when I lay down on my back, breath in or out deeply, cough or sniff, and hold my right arm above my head. It hurts worse on the side of my chest under my arm and when I press on my ribs at all, front or side. I don’t know if it’s related, so I called my regular doctor’s office who told me to call my pulmonologist. When I called the Pulmonologist’s office, the staff called back and told me to go to the ER. I really don’t want to go to the ER, as I’m not sure it’s related and don’t want to pay the high copay for nothing, but I do want to know what to do about the chest pain. Is it related to the cavity? Is going to the ER really necessary?