No,calcification in itself is not cancer,nor precancerous.They are abnormal looking cells,that might,or might not turn into cancer.I did have check-ups,but,because of my age at the time(in my 40ies),they were done every few years,even though the calcifications were present for a number of years.Because of the long gaps between mammograms,cancer did develop,but,by the time it was detected had already grown into a 10cm mass.(It became apparent that it had been overlooked several times).
After surgery ,chemo and radiation I am happy to say I have been cancer-free for 15 years now.
I understand your concern and worry ,especially regarding the nodule in question.You are doing all the right things,and,please keep in mind that anything discovered now would point to a very early stage which offers the most successful treatment options,if any are needed for that nodule.
Please do not overwhelm yourself with worry and get stressed out.Go one step at a time,take in the information you will get,ask questions as many as you need ,even if it irritates people!Stay in charge of your body,don't let others take control of your well-being,and always stay on top of things,regardless of the outcome.
Sending you positive thoughts and the best of luck!