its just stress. if your that worried go to the doctors.
i have also been getting headaches and cramps worse than normally. if it isn't stress what else do you think it could be? (sorry for bothering you i'm just little worried)
then its possible its from the stress but when your young your periods arnt always going to be regular,
im 16 and my cycles are normally like 17-20 days (without it)
I dont think it's a reason to see the doctor unless it keeps happening. Stress can absolutely alter your cycle.
how old are you?
it could have been from stress then again it might not,
you should go to the doctor just to be safe.