What do you think if I shat myself in school?
That's unfortunate, why did you shit yourself in school? It must have been a dire situation.
I just couldn't hold it in any longer.
Accidents like that can happen to children and it's perfectly normal to be embarrassed when things like that occur. I think the other students will probably forget about it in time and eventually it will be become a funny story for you to tell when you are older.
I suppose you are right. It is what it is and it's too late to change that.
Yeah, it's not your fault and you are being really cool about it too. When nature calls, it don't care who you are or where you are. Maybe in the future, try going to the bathroom early even if you don't need to go, just so you know you won't have anymore accidents.