I would leave the diagnosing to the psychiatrist. Be as honest as possible. Keeping a mood journal is a good idea. You can then see if there are any patterns to your moods. You will also have more information to give the pdoc if you decide to make an appointment.

Alternately, you could see a therapist if you have malady to work on. Therapists can sometime get a sense of where you are - though they don't really diagnose. They may refer you to a pdoc. If you find out you have bipolar, a therapist can be helpful especially if you are reluctant to go on medication.