When is the best time to take Plan B pill after having unprotected intercourse?

Dear Ask The Doctor: Hi, I'm Jenna I'm WP yrs old... my concern is about the plan B pill. me and my boyfriend had sex two nights ago, unprotected. I got my period right after having sex.. what are the chances of me becoming pregnant... is Plan B pill necessary? Thank You.

I honestly think it will be unlikely for you to get pregnant from the circumstances you just described. I am not saying though it is impossible; but the possibility is very slim. It is also unnecessary for you to take the plan B pill now because it may not be very effective anymore. Plan B pill is effective when taken within 72 hours (3 days) of unprotected sex. Effectivity is ~90-95% when taken within 24 hours and decreases to ~55-60% when taken within 72 hours (day 3). I do hope I have answered your question. Take care always.