Levonorgestrel
"Please don't judge this post..I'm here to share my experience with Plan B and provide some hope for others in the same situation I was in. I stupidly had unprotected sex more than once in a several week time span. I took Plan B twice within a few weeks of each other. Up until then I had pretty normal periods and no major issues..After the second time I took it I had insane cramps, back aches, sore breasts, you name it.. I was convinced I was pregnant but all tests were negative. I just got my period..exactly 8 weeks after my last one. So taking Plan B, especially more than once, really messes up your cycle and the added stress of thinking you may be pregnant doesn't help either. I'm also well over the "weight limit" and it still worked."