Disconnect resulted in exp loss and quest progression

Exactly as the title says. My level 18 Druid Colate recently leveled to 18 after finishing the bandanna and Vancleef quest from Deadmines. I went to Stormwind to turn in the quest related to the letter Vancleef drops when I randomly disconnect. I couldn't log back in so I was guessing they were having server problems. I come back an hour later and I regressed back to level 17 and I was back in Westfall with the incomplete quests for Deadmines. The exp was roughly 5 bars and running Deadmines again isn't that bad either. Just wanted to put this out there, other people might be having the same problem.