Daisies4monkeys

This should not prolong your period.

Take a pill today, and keep taking one a day until the end of the pack. Then either start your new pack a day early, or else, if you don't, and you want to have sex, you MUST use back up until seven consecutive pills have been taken perfectly.

Your other option is to open a new pack now, and take a pill from it. Label that pack as "extras" and keep it on hand for situations such as these.
That way your schedule and efficiency won't be messed up at all.

Talk to your doctor about doubling up on pills to stop the bleeding or taking supplemental estrogen. If the bleeding is heavy and has been going on for 11 days, I'd say a visit (or at least a call) to your doctor is in order anyhow.