Reaction isn't always good way to tell. There is medication induced mood disorder or bipolar which is not actual bipolar, it will stop when the medication is stopped and not return. Then there are bipolars who do not get manic from antidepressants or not every time. The symptoms you experience are the bigger indicator especially when unmedicated.

I'm sorry your new dr is not in agreement. Were you previously diagnosed? Sorry I can't remember at the moment. I hope the Prozac will help you.