I DID NOT HAVE SEX, but had gotten pre-cum on my labia. I'm still a virgin, what I want to know is...

Who has taken plan b within LESS than 24 hours and had it work? I've had a period since I TOOK PLAN B ON JUNE 2nd and my next period was due today, I didn't get it so i'm really worried. I had gotten pre-*** (a little drop of it) on my labia june 2nd and took the pill 2 hours later. i got a period on june 8th and now i'm waiting for my next period. do you think there's a chance that i'll still be pregnant? what should i do if my period doesn't come today? I'm so scared.