My period started Wednesday 10/15/14, it was pretty light during this time. Normally they are kinda normal lasting about 4 days. It ended Friday night 10/17/14, well last night 10/19/14 I started feeling nauseous and wiped n there was bright red blood... I do have unprotected sex with my boyfriend, however I do take bc pills, and we have intercourse about 4 to 5 days a week.. could this be implantation???