I had sex just a couple days after my period. The condom ripped and he came inside me, so I immediately took Plan B. About 3 days later I started bleeding as if I was on my period, even though it had ended less than a week before. Now its about 8 weeks later and I still haven't gotten my period. I know I'm not pregnant because I took a pregnancy test and it came out negative, and because of the Plan B. Any advice?