I had taken Plan B on April 1st and had withdrawal bleeding on the 7th. For about 5 days it was similar to when I get my normal period (even though I wasn't expecting it until the 14th-17th) after the 5th day I was just spotting very lightly, only noticed every time I wiped and that had lasted up until the 18th. So in total I was bleeding/spotting for 12 days. I took 4 pregnancy tests that were all negative. The last one I had taken the day after my expected period so I'm confident that I am not pregnant. What I am wondering is, could my period be delayed even longer than what's "normal" for people who've used Plan B because of how long I had bleeding/spotting? Would my uterine lining need more time to build up before it would shed again? Or would I just count the withdrawal bleeding as my period & wait for the beginning of next month for my next period?