And I say be calm and caring because obviously you don't want to just explode with the paranoid ARE YOU CHEATING?!?!?! thing because that will turn her off and make her immediately go into defense.

You will reach NO RESOLUTION that way, ever.

Even if it's out of the ordinary for you to intently listen and be gentle with her... you gotta do that shit cuz remember... this is really about you, making sure YOU'RE not being wronged, and making sure you're not wasting your time in a dead-end relationship.