What is this cut thing in my mouth?

I dont really know how long it has been here but i have like this thing in the corner of my mouth. It almost seems like a cut that has a scab over it but my dad says its just a canker sore. Im almost sure it is after researching about it, but it has been here at least a 1 week and a half to 2 weeks. Dont act all dramatic but i just wanted some urance that I will be fine. plz answer! :)