Plan B One-Step question

So I had a oopsie about a week ago now, and I took the pill 1 day after, and the directions say I can do it within 72 hours so I just wanted to know if any of you girls had the symptoms that it says you may have and if it really worked for you or not, Cause I am a smoker and I would hate for anything horrible to happen and since I'm a smoker do you think it would downsize the effect of the pill? I just need a little more info to feel more comfortable about this whole thing, I'm supposed to fallow up with a doc soon.