Fluoxetine brand change

hi everyone i started prozac two weeks ago 20 mg.. and got a new perscription yesterday. the brand has changed and today i feel very nauseous and hot like im gonna vomit. can a brand change cause more side effects or am i coming down with something terrified of this virus aswell. i wonder if anyone else has had this happen. also can fluoxetine cause side efects like two weeks after starting.. ?

hi