"i just wanna share this with girls who are worrying and freaking out cause i sure did. i took plan b cause i messed up on my birth control but also took a new pack of birth control the day after plan b, i didn&#039;t get my period for the month in february at all which freaked me out but i ended up getting old blood a couple weeks later and finally a month later after finishing my birth control, during my placebo week i am on my period right now. so i wanna say i know it&#039;s hard not worrying about if plan b works or not but it really does. if you take it with birth control i would say it throws off your cycle."