Stop procedure when block is broken

I'm making a procedure that starts when the player places a block, when he does, it spawns particles and then destroys the block. But I have a problem: If you break the block before the procedure does it, the particles keep spawning. I'm trying to make the procedure constantly check if the block has changed and if it happens then make the procedure stop, but I don't know how to do it. There's certainly other ways to do this but I'm unable to figure them out, please help