Hooray for you for taking control! Don't let go of that tenacity!
A cyst is fluid filled and can change throughout the month. I think there is low risk of a cyst being anything but benign (key word is low). 80% of breast lumps are benign, so odds are on side. A lump can also be a solid benign tumor, called a fibroadenoma. There are loads of other benign breast conditions too....I do not know much about
calcifications, so I can't address those questions.
You can insist on a biopsy and if there is something there, most of us will recommend that you get one...but not every doctor will do so. Understandably, they cannot biopsy every lump or bump...but if there is something there, please pursue it. Remember you can always get a second opinion from a breast specialist.
Good luck and keep us posted!