Hello, My Last Period Was On January 2nd, My Periods

Hello, my last period was on January 2nd, my periods are usually not regular and can come at any time in the month. My fiance and I have had protected sex throughout the month and he also has been not "finishing" inside of the condom because both of us are not quite ready for a baby. I was told my next period should have started on the 26th of January but still haven't started. I've had two negative pregnancy tests and still no period or symptoms of being pregnant. What do you think?