Pain sensation inside while on acid.

Every time I've done acid (3x) I get a pain in my abdomen area. Like tight/squeezing sensation. I always have to lay down and try not to freak out. I calm myself but im unable to enjoy it the high after that. It happens after the first peak and then doesnt go away until I come down. I never felt the pain while sober or any I ther time just acid. This doesnt happen with shrooms or weed only acid/LSD.

Any one else have similar experience?