Could I be...pregnant ?

Ok this morning Im having food aversions.This whole week,I dont know if its my imagination but I've been feeling flutters in my lower stomach.Ive been having unprotected sex since January and I got my period every month right on ime.I took plan b in March and took one yesterday.I';ve also been drinking moderately during the weekend.I drank last night so could it just be a hangover ?? I dont feel like eating what I normally eat !