Pregnant or Birth-control??

Hello ladies ! I'm on my first week of birth control .
Anyways on January 21 I had unprotected Sex with my fiancé, long story
Short a week ago I got my period, I started birth control.
This past week I have been nauseous and dizzy, things I used to love eating, I hate . My fiancé cologne used to smell sooo good now I hate it ! Please helppp!