I used
this tutorial years ago (it says witchcraft, but there's way too much
thinking involved so I consider it psionics.
) I introduced it to an acquaintance on another board, and later he reported feeling a "cork" where the third eye would be, and the course writer does describe a "pressure". Mine personally presents as tickles around the third eye but slightly to medially painful aches at the heart and solar plexus. If it's not so localized, (say migraine or tension-type head ache,) I would say it's dehydration from extended meditating... but if it's localized pain then I'd say it's normal! But your guess is as good as mine why that is.