Ok so 12-20-09 I started my period , I read that while on it I could start bc so I started bc on 12-22-09 , I left it on my nightstand and it was missing on 12-24-09 so oi started a new pack (different brand) on 12-26 / 12-27 . My fiance and I had unprotected sex where he did cum inside me twice on 12-30-09 , and on 1-5-09 I started to have brown discharg (according to bc period should come this sunday) I woke up on 1-6-10 to a little blood and thought it was my per but it is now again a very light brown spotting ! What could it be , I keep hearing implantation bleeding , any thought ??