Recently when I logged into StackOverflow, I found that my reputation has decreased. To find out the reason, I looked at my reputation history but couldn't find any reason why my reputation got decremented.

After some more research, I found, one of my question has been deleted from StackOverflow which I've flagged for deletion about a month ago, because of which all my associated reputation has been decremented.

I think, it would be better if a notification is sent to OP after or before deleting question especially if it has been a long time since flagging for deletion.

Actually, I flagged for deletion because of multiple downvotes. But after I've edited my question, the downvotes have been decreased and I don't want to delete my question now.