Hi Thessf14, and welcome. Variations in tumor markers test like the CA 27-29 can be disconcerting and stressful. As @cindylb aptly said in an earlier message in this thread "Tumor marker tests are one tool doctors have to monitor but they can have great change and variables." And @mom23boys said "people's numbers bounce around and no two people seem to have the same starting point or "normal"."
Tumor markers are a simple non-invasive test that can give a signal for further investigation – the proverbial canary in the coal mine. Sometimes the fluctuations may indicate a progression of disease and sometimes not.
I'm sorry that you got this reading on a Friday going into the weekend, especially when it may mean nothing. Were you able to talk to your oncologist today or to leave a message on your patient portal? What type and stage of breast cancer do you have?