If you have a regular 28 day cycle, then your period was due on the 3rd of Oct, and depending on the sensitivity of the home pregnancy
test, it may have been too early
to measure the small amount of hormone in your blood two days ago. I'd recommend taking another test this morning since you still haven't gotten your period, and waiting another two days and testing again if it's negative today. (hCG doubles every 36 hrs or so)
Best of luck!