I have been doing lots of research and have found many conflicting arguments on this topic. I recently had unprotected sexual with my husband right before he left for his deployment.The next day I expressed my concern for having a baby while he was away so I tested to see if I was even ovulating and if it would be a problem. I tested for my LH surge and sure enough I was having it. So I took plan B, thinking it could help. The next day I tested to see if I was ovulating again and I still am. Does that mean it didn't work? Does it not work if you already had the LH surge?