Had a hard time threading my leash rope, did i damage plug?

For some reason I had areally hard time threading my leash rope through the plug. I had to spend about 10 minutes trying to force it through with needle nose pliers and it was a pain! I was pretty careful not to damage anything, but i wonder if i was being too ruff with a sensitive area? What exactly would happen if i did loosen or gouge the plug? Also, is there a clear sign that you dinged your bored? Im afraid of dinging my bored and not realizing it and letting it fill with water. Oh and if you didnt get im a total n00b. Thanks for taking the time to read and answer this. 
