I've done it ... my cheek makes the keys press. Usually the # 6 for some reason. If it happens again, while still on your call, pull the phone away from your face and see if you can see any numbers on the screen.
If the screen is not turning off while you hold it to your ear then you can still press buttons with your ear/check/face.
That or someone is playing a trick on you on the other end.
I appreciate everyone's comments and I agree it sounds like the phone is hitting your cheek and pressing numbers. If you are not able to duplicate this issue when using speakerphone, it sounds like this is the issue. The phone does have a sensor to test when the phone is near your face. If you move the phone slightly or move your head, or your hair gets in the way, it can block the sensor.
I know this thread is a few days old, but it's most likely the minute reminders you're hearing that beep every minute you're on a call. You can disable this in Settings.
No as I specified in my original post the minute alert is shut off. Also the touchscreen is black and inert while on the phone so I don't think its my cheek. I also make sure not to touch any of the physical buttons on the phone. I may take it into a verizon store and see what they can do since I have been having other issues especially since the recent software update. Thanks for all of your replies though.
After having this happen repeatedly I am thinking about going into a verizon store to see what they have to say. I have not been able to replicate the sound by intentionally pushing any of the buttons on the phone even its not right near my face. Additionally when the buttons do sound they make a different sound than the one I am hearing over the phone. Any further ideas?
I had a similar problem a couple of times. Noticed that the dial pad was on the screen and my ear was pressing on the numbers. Hid the dial pad and the problem went away.