Top left corner force touch trackpad problem.

I've been using my MBPR 13" for about 8 months now. I don't usually use my trackpad much since I use a wireless mouse most of the time.

I tried using force click for the first time and noticed something odd whenever I press the top left corner of the trackpad. It feels heavier and firmer when I press at that corner as if there is an actual button there. I understand that the new force touch trackpad uses vibration to register each press. I even tried shutting down my MBPR 13" and pressed every sides/corner of the trackpad, the rest is flat and unresponsive but the top left corner does respond with a *click* sound.

I'm wondering if that corner is meant to be like that or is my trackpad broken/loose on the top left corner? Does Apple warranty cover minor faulty trackpad?