There are many conditions and even emotional states that can mimic bipolar though, imho.

If the episode was triggered by some specific event, it could be very much it.

Also depends on how bad your depressive episodes are.

Not saying you do or don't have it, but I don't think that being diagnosed is a decisive factor determining if you indeed have condition. Because... misdiagnosis do happen. So maybe it'd be good to do a review and get second opinion and go on from there.