The 5-day RU486

New 5-Day 'Morning-After' Pill Tested For U.S. Approval

"But a novel morning-after pill that was approved last March for use in Europe has undergone new testing for safety and efficacy in the U.S. The emergency contraception, ulipristal acetate (ellaOne), for women who have had unprotected sex, claims to have enough potency to protect them from pregnancy for up to 120 hours after intercourse. The one similar pill, levonorgestrel, is already approved in the U.S., but it is effective only up to 72 hours."

and the side effects are:

"Side effects of ulipristal acetate were mostly headache, nausea, and abdominal pain, but the effects were mild to moderate and resolved spontaneously, according to the researchers."

so it sounds like a side effect might be that you would still feel pregnant