Well I would have never done that if I were you!
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.
If this was the reason, then bravo! There might be a +1 in the helpfull flags of your profile. I am not sure whether this would cause a plus one because I never flagged my questions or answers.
Actually, I flagged for deletion because of multiple downvotes.
If you want to maintain a rep, then I guess you'll need to delete this question too. And keep deleting your questions and you will get banned from asking more questions. So stop doing so, and start editing the posts to make some sense in them!
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.
Its not facebook you're talking about, its Stackoverflow. You cannot get live updates of everything! So I guess there is no chance for you to get updates from moderators about every action of theirs. But yes, you get live notifications of comments and other site achievements by you.
What you should do
You should try to edit the questions instead of deleting them. And also there is a delete button on your posts too. You can use it! But keep it in mind that too many deletions or too many down votes would lead you to a ban!
And also, the post might have been deleted or closed due to voting. Or moderator have himself deleted the post. Because once you flag it, moderator takes action within 5 minutes or next to it. So a post deletion after a month, man were you hiding it? Or was it private or something :/