White spot on throat

Suzy
I have a white patch (about the size of a pencil eraser) on the left side back of my throat. My throat doesn't hurt, it more just feels like something is there. Anyone know what it could be? I'm going to gargle with salt water and see what happens then. 
Just curious if anyone's had that before. I can take a pic but thought I'd ask before doing that haha. 
Will be seeing my dr this afternoon so if it's still there I'll ask him too. Thanks!