so I took plan b on December 9, I got my period on December 14 and I haven't stop bleeding yet, also the blood is almost black now, and there is a lot of blood cloths, like more than usual amount for me, should I be concerned? or is it just side effect? and have you ever experienced something like that? p.s.this is not my first time taking plan b pill, the first time it messed up my cycle a little bit, but nothing crazy.