| [NOTE: Are you looking for the answer to the question about tampons featured in our recent online newsletter? It's available here. For the answer to the question above about emergency contraception, please continue reading below.]
It could be. Irregular bleeding is a common side effect of taking emergency contraception (EC), sometimes called “the morning-after pill.” It is possible that the first menstrual period after taking EC may be early or late. If a woman is not pregnant, her menstrual cycle should return to normal the following month. Frequent use of EC may cause periods to become irregular and unpredictable.
EC can reduce the risk of pregnancy if started within 120 hours — five days — after unprotected vaginal intercourse. They work best when started within 72 hours — during this time they can reduce the risk of pregnancy by 75–89 percent. The sooner, the better.
EC is not as effective as the regular use of ongoing contraception —such as the IUD, the pill, the patch, the ring, the shot, or the implant. EC does not continue to prevent pregnancy during the rest of the cycle — other methods of birth control must be used for continuous protection. | 
