It depends. My initial appointments have lasted 20-30 minutes. I've seen three different pdocs in the past few months. My maintenance appointments are shorter. 15 minutes at the most. They seem to only be looking for changes since the last meeting and they want to know how my med adjustments are working for me.

3 minutes seems neglectful. I would speak up and make sure he or she knows you have items you'd like to discuss at your next visit. How long until you go back?