It seems like I am going through the same thing, I had my last period nov.22, skipped dec, and January 6th through13 I spotted pink and bright red, I had headaches, tired all day, stomached,and cravings, I had a blood test did on jan15, came back negative, now it is feb 06 and my stomach is big feels like a big knot inside and my breast are very swollen and my headaches are still there, and I just know that I am pregnant but I believe that it was to early to show up in my blood so I will be going back in a about two weeks, so I think you may have tested to early wait two weeks and test again because you do have all the symptoms. Good luck!!!!