I started spotting 2 days ago. It was very light the first day and started very late at night. It was light pink and then yesterday it was still light, but a little more than before and it was a mix of brown and red discharge. Today it was also lighter than my normal period, and was brown and red again. My period isn't supposed to start for a week from now. I haven't been late or early in a year on my period so I'm confused. I did have sex about a week before I started spotting, and it was on one of my fertile days, but my boyfriend wore a condom. What are the chances that this is implantation bleeding or just an odd period?