Could it be something bad if I have vaginal pain?

Unlikely. It is possible that you could have endometriosis, or fibroids, or a rash or even a skin condition in the vagina. But it is very rare that vaginal pain is a sign of something bad, such as cancer.
Possibly. "vaginal pain" is not specific enough to give any solid answer, but this type of symptom could certainly could be caused by any number of problems. The most common might be related to infection (vaginal, or even urinary), retained foreign object (such as a tampon), injury, or prolapse of some sort. If it persists, have an evaluation.