Levonorgestrel
"I took this pill after 24 hours of the accident. 5 days later I got what they say is a "Plan B Period" even though I got that I was still stressing think of the what if's, the next month my period was late 7 days late in fact but it eventually came. I am so thankful for this pill. What I learned is don't stress if you take the pill directed you will be fine. The only down side was I got extremely tired"