Plan B is best taken within 3 days of the unprotected sex so 5 days later is too late. The only thing you can do is wait and see if your period comes. If it's more than a few days late, take a test.View Thread
Skipping a period usually means you didn't ovulate and no ovulation usually means no period. It's common and will happen to most women at least once during their reproductive years. Also, just because it's never happened before doesn't mean it can't/won't.
If you miss a second period and are still getting negative test results, see your doctor.View Thread