The first day of my last period was July 27 and now im 18 days late never have been late other than when i found out i was pregnant with my son who is now one. i have been having some light cramps in my lower back and my lower stomach, i am always tired, i cant stand to long, and been having some slight breast sensitivity that will come and go! i have took 1 test and it came back NEG. should i wait to take another one? or go to the health dept and get a blood test done? please help me!!!