Nausea from plan b or just going to get period???

All these symptoms are freaking me out! Im a little nauseous in the morning but would it be because I got plastered last weekend? My eating cycle has been messed up because Ive been so stressed about the plan b problem i havent been eating/drinking correctly. I wake up every morning like my stomach is empty and i get hungry. Help! So many hormone unbalances in my stomach. My period is coming next week but all this stress/nausea/cramps etc are freaking me out!!!