I think my girlfriend has vaginismus

My girlfriend is a virgin and we have tried to have sex twice both times I really couldn’t get it in much. And I don’t know the difference between just really tight and vaginismus, what made me jump to this conclusion especially is she can’t use tampons because they hurt to get in.

So I’ve done some research and she plans on using some stretches I’ve found. Will the stretching make any difference? And should she go to the doctor?