plan b

Okay I really don't want to hear "it's bad for you, it does this and that.." I just want to know is I've heard it only works if you weigh a certain weight. Is that really true? I remember a while back it saying you have to weigh 163? Or 165? In order for it to work and I weigh 185. Is it in full effect or how would I really know? I've taken it twice, last time I took it I bled the day after for like 10 days and it was heavy. Now this time there's no side effects on me or nothing? It's been I'd say 4-5 days since I've taken it. Does me being the weight I am have to do anything with it?