[taylalatbh.]

By the sounds of it, you're not pregnant. You took the Plan B right after having sex. And you could go back and see the nurse for another test if you're still worried. The Plan B could have messed up your periods, and it could take a few weeks to regulate back out, but if you have any problems you could talk to the nurse.

And as for if you did become pregnant, cross that bridge when you come to it. There's no point worrying about it now when you don't have to. Just make sure that you're careful when having sex, and see about using two types of contraception, just to be safe.