If you've missed two pills, your pregnancy protection is compromised, yes, and your uterus may indeed decide that it's time to start the bloodworks. You could try to stave that off by using the other pills, but as they're a different brand, you're likely to experience side effects (like breakthrough bleeding!) as your body adjusts to that brand, and as they're expired... Well, I wouldn't trust them for pregnancy protection and I wouldn't be ultra-surprised if they allowed extra breakthrough bleeding anyway. If you'd only missed one pill and could resume the rest the next day, I'd say go ahead and use just one Aviane pill to fill in the gap. If you'd had recent ejaculation in the vagina, I'd say that it couldn't hurt to try to keep the ovaries hypnotized, despite the high risk of side effects.

But if you've used backup contraception for all sex within the last week or two... I'd say it'd be simplest to just have a withdrawal bleed while you pick up some new Tri-Sprintec. Consider yourself unprotected from pregnancy at this time. Take the new pills whenever you feel it'll have you back on schedule, and after 7 days, your pregnancy protection will resume.

I hope that helps!