The only thing that seems off is that your BF's mom was asking about your health information at the office and that could be a HIPAA violation. As a nurse she should know she shouldn't be trying to get or access patient information like that, especially her son's girlfriend. But if the conversation was verbal and there's no record of her accessing your chart on the computer it will be very hard to prove she had violated your privacy. There isn't a private cause of action for it. You can report it to the practice and the nursing board and she might get in trouble. But if this was years ago and there's nothing to prove she did it there's not much they can do.

Tests can be inconclusive or not accurate. They did a blood test to be sure. You don't have any real damages from that. People get upsetting results every day that aren't confirmed with further testing. It's just part of practicing medicine.