Problem with Mic

So I got a headset a while ago and it worked fine.
All suonds came through my headset, not including my own voice.
Though now Ive reinstalled my mic, the sound of my voice can also be heard
through my mic speakers which can get VERY annoying hearing every breath I
take.

Is there a way in-game or in the OS that I can change this back to what it
was before (before, my own voice was probably coming from my speakers since I
never have them on) The game is Team Fortress 2 but it also happens when I'm
not in the game.