The other day my right side of my body went numb in my fingers and my mouth, i think i have hurt the top of my neck also. .do you think it's a stroke?

Probably not: It's difficult to connect mouth numbness and loss of sensation in fingers to an anatomic problem at the level of the brain--especially if these symptoms were not associated with loss of strength. Has this problem recurred? Do you have any weakness? Are there any other areas of facial numbness, difficulty with speech or swollowing? I recommend seeing your physician for detailed neurological exam.

Could be: Although young, strokes can occur at age 19. Other causes include partial seizures, migraine variant. Whatever the cause, you should urgently see a neurologist for diagnosis. Neck injury would not be expected to cause numb mouth.