I had unprotected sex mid Febuary and wasba week late for my period. When i got my period, exactly a week late, it only lasted a few days and was very light and more of a brownish color rather than bright red. I am now 11 days late for my period and have taken 3 urine pregnancy tests, all of which have been negative. I have increased appetite, light cramping, back pain, increased need to urinate and fatigue. What should I think? Pregnant or?