Am I pregnant?

Patient: My husband and I were intimate on December 28th and then on January 7th. I started my period on December 26th. My cycles are always 26 days apart. I was suppose to start January 21st, but it did not arrive. I took a home pregnancy test on January 25th and came out negative. I waited until January 31st to take another, still negative. On January 20th I felt a bit of menstrual “like” cramps, but nothing ever happened, they subsided the next day. It is now February 2nd, and have still not started my period, therefore I am now 12 days late for my period. Could my results just be wrong, even though my last test I took was 10 days after my missed period?