The -2 you lost were because a question you had edited (which gained you +2) was deleted by the author. When a question is deleted, the reputation changes associated with it are reversed as happened here.
You also lost -4 reputation a couple of days ago because 2 questions you had edited were migrated away from the site because they were off topic.
Another -4 came a few days before that when two questions you had edited were deleted. One by the OP and the other by the system since it had been closed and had attracted no votes for more than 9 days.
Unfortunately, since deleted posts are only visible to >10k rep users, your profile doesn't show this information. You might be able to see the migrated ones but not the deleted ones.