White spot on my tonsil?

this morning I woke up and my throat was hurting REALLY bad but only on the right side. I looked in the mirror and didn't see anything and the pain continued so I looked again and there was a big white spot on my right tonsil that looked like a canker sore almost. I don't think it is a canker sore though because I have chronic canker sores and this doesn't feel like a canker sore it feels like a really bad sore throat and hurts when I swollow but not as badly when there's food. I haven't had strep since I was a child so I don't really remember but I thought there had to be a bunch of white spots does anyone have any ideas of what it is?