Can a person misdiagnosed present manic episodes with antidepressants and never had one before the treatment?

Yes: For many reasons this is possible; but one very common situation is that the patient was not diagnosed at the time, and symptoms were not so notorious for the patient (bipolar patients often feel just normal during manic episodes; egosyntonic state). Your dr will examine and evaluate you to determine what was the case, if diagnostic is still not clear for you, you might obtain 2nd opinion.

Yes: A person may have been diagnosed with unipolar depression. Maybe they never presented with clear manic/hypomanic symptoms previously, the right questions were not asked or the person is not a good historian. An antidepressant might trigger mania or hypomania if there is underlying bipolar disorder.