Why does Plan B Cause Spotting?
Glad you asked...
Plan B can cause spotting because it is stopping an egg from being fertilized, and a lot of time it makes your body think that it is time for your period, so you will spot.
leyash, Answers Expert
Then again, this answer might help you...
Plan B can cause spotting.in some women because of the hormones it contains. It consists of chemicals that match those found in the ovary. Also, where you are in your cycle can affect your bleeding.
elliottsinaz08, Answers Expert