Do NOT double up tomorrow. There is no reason to. A pill is not considered "missed" until it is twelve hours late. With a combined pill, taking it a few hours late is not an issue at all. In fact, with combined pills, the literature with most of them says that missing one pill is not cause for concern, so long as you don't miss any more.
You're fine, you don't need any back up, you don't need to take two pills tomorrow.
Some women will spot if they take a pill late, but it won't effect your protection to take it late once. Don't make a habit of it, but one time late will not effect you.
However, if you're on the mini-pill (Progesterone only) you must take it within an hour of the same time daily to prevent pregnancy. But with your pill, five hours is totally fine.
What pill are you on?