[Verità]

Your chances of getting pregnant are very, very slim. More or less next to nothing. Once sperm is exposed to the air, it dies away very quickly. And then, in order to fertilize an egg and therefore impregnate you, it would have to travel all the way to where an egg is located, and then assuming it finds it's way to one, it would then have to successfully fertilize the eggs. I think you're safe, especially since you took Plan B, but there's no harm in taking a test in a few weeks time just to be sure.

It can be a huge relief to double up on protection, therefore decreasing the odds even more than using a condom and Plan B. The next time you visit your doctor, you should ask about different methods of birth control. In order to have an idea of what you think would work best for you, as sometimes pills or shots aren't for everyone, I would look at this thread. That way, you'll have an idea about what you're using, and you'll have a chance to think up some questions for your doctor before the appointment.

Take care!