Late and negative

Jennifer
So I was suppose to get my period on 1/26 I still have not gotten it. Monday 1/30 I had a headache and was nauseous and some food smells didn't smell to great. I took a test that same day and it said not pregnant. I still have not gotten my period and have been regular since I got off birth control on September. People have told me you can have low hormone levels that tests read to determine pregnancy and to take another one later in the week. Is this seem normal? This is my first time trying to get pregnant.