I had sex with my husband on march 31 he left April 2 to Georgia for some training, he got back May 11. AF came April 10, 2 days early and it was light like it usually is my husband got back May 11 and AF was scheduled for May 10th is May 20th and no AF. I have taken a HPT but I have had BFN I feel tired and I started feeling nausea. I started throwing up tonight. I think there is no possibility of pregnancy but my AF is regular and I have never missed it before. I need advice on what may be going on.