condom malfunction...

Um. I had my Mirena removed on December 29th, after having it in for a little over a year. I haven't started on a pill or anything because I'm seeing an endocrinologyst soon and they don't want me on anything yet. So..my boyfriend and I just had a condom malfunction and I'm sort of freaking out. Are the hormones still there..? Should I go get the Plan B thing tomorrow? How much is it usually?? I don't know how I will react to the hormones in that, have any of you taken it and had anything crappy happen? I'm really sensitive and have a panic disorder as well, so I'm not sure what to do.
HELP!