I'm having breakthrough bleeding due to a missed pill!?

I had missed my pill and taken it the next day around my usual time (7:00) because that's when I realized I forgot. So I took the other day's pill 5 hours later. The next day and ever since I'm having light bleeding/breakthru bleeding. It's been almost 3 days. I have a yearly checkup this weekend I HAVE to go to, but if I'm still bleeding, I'm screwed. Will this end by Saturday? What can I do.