It takes time for the swelling to go down. Remember, tissue was majorly moved around to make room for your vagina - that's a bit of a medical trauma. Don't give up dilating - the early post-op phase is a critical time for keeping things open vaginally. I waited till at least 3 or 4 weeks post-op before I even considered moving up size-wise for dilators. Even then, until things stretched out more, it was uncomfortable (almost painful - the first time I used a lager sized dilator, I basically exclaimed "oh my gawd!!!"). As it is, for me, to this day, when I do dilate (not very often anymore since I'm almost 15 years post-op), I'll start off with a smaller sized one for a short period of time, moving the the main (significantly larger sized) dilator, for the remainder of the dilation session. Don't force things with a larger dilator, if the pain becomes severe - otherwise you risk tearing things in your vagina.