Crying out of no where

My 15 mo old will start crying and grabbing her mouth out of no where . And she will start crying real tears like something is wrong . Even when she is eating she will start crying tears out of no where . Should I be worried ? I looked in her mouth and yes her molars are coming in ,but idk if that’s the problem . She’s been doing this for like a week now . I give Tylenol just in case it’s her teething but I’m not sure . It’s starting to freak me out 😩