Good idea...three latest pay stubs should be okay if a confirmation cannot be done in short time, at least the pay stubs give a "current" salary situation, right?
Are you working? even for this matter won't help that much...at least could be send the message that still money is getting in the household. But anyway you would need to do a new I-864 with the new information.
Now a question for you all, what happen IF at the interview the IO never ask for it? Let's say just ask for how you met and give me some pictures...and that's it. Do they should give anyway the new I-864 for sake of the pure-clean process or just use the "don't ask, don't tell"?