iud and periods

So I've seen several posts about girls getting the iud and then eventually having no period. I know there are different kinds so is it just cuz of a specific one? Before I got mine(paraguard) my gyno specifically said my period would be way heavier than it usually is.. it kinda fluctuates, but I'm just confused. Like I haven't heard anything about a correlation btwn the iud and no longer getting a period. I did a lot of research before I chose the one I got too. I know I'm fine, but what about these other girls..? Just wondering.