It will simply further confuse your body. You've gotten your body pretty confused by skipping a couple pills (accidentally, of course) and taking the Plan B twice when it should only be once in a blue moon. If you continue to not take the pill as it should be (not missing and letting there be a week between), you may find yourself still bleeding regardless. If you're still bleeding heavily by the end of this placebo pill week, I would call your gynecologist for advice. She may advise you to take the next pack or have other advice for you.
Speaking from experience, you can still bleed for ages while on the pill. I had some pretty heavy breakthrough bleeding once despite taking my pill at the same time daily that lasted a month. It was not fun. My doctor suggested I return to taking the pill to have a period every month for a while before returning to taking it to have a period once every four. The body sometimes needs to reset itself.
A suggestion because I know it can be hard to remember to take the pill every day (especially when life gets hectic): try setting your cell phone alarm to go off daily at the same time and take the pill at that time. If it's at some point other than when waking up, I would keep the pill pack in your purse with you so that when this alarm goes off you can take it.
You've been taking a ton of extra hormones, having taken plan b twice while on the pill. Yikes! That's why you're having all these problems. You're not supposed to take plan b while you're on the pill. They're are very explicit instructions that come with your pill pack which tell you what to do it if you miss one. Taking plan b while on the pill will cause a lot of bleeding issues. That's what happens, it's why you need to follow the directions in your regular pill pack.
Thanks for the response! I'll definitely follow the advice -- just curious though, why would it make it worse?
Take the whole week off because you need to. You do not have to actually take the placebos as they are just there to serve as a reminder to start your next pack on time. Your period will not stop just because you start the next pack. It may actually make it worse if you do.