Little confused

Okay so Me an my husband had sex on my birthday Jan 27th like mid night we was super drunk , but then I started my period that morning . I got off my period Sunday we had sex again that Monday . Well I notice my nipple was super dark an last night I had the taste of a pennie in my mouth all night . I been hella nausea. An I know it’s not possible to be pregnant especially since I had a period but maybe I ovulated early or something why am I having pregnancy symptoms