Last month, on the day after my period ended, I had unprotected sex. While he did not ejaculate inside, I still decided taking Plan B immediately was the best decision.  So roughly 12 hours after, I bought and took Plan B. Now, I am 4 days late for my period and I'm pretty nervous about it. Yesterday I took a pregnancy test, which came out to be negative. But now I'm anxiously waiting for my period to arrive. What are the chances that I could actually be pregnant? Or that my cycle is thrown off because of the Plan B? Please help! :( What should I do?