I'm almost 16 years old. My boyfriend and I had sex last weekend and a couple of days ago, we didn't use a condom (we didn't have any left and the nearest shop was closed), and I'm not on any kind of pill. My period isn't due until the beginning of March, but today I've been bleeding. It has only been light, very thin bleeding, unlike my usual period, and it has kind of been on and off throughout the day. My breasts have also been very sore recently (maybe they're just growing, I don't know), but I'm getting a little concerned.
Could this possibly just simply be an early period, or does this mean something else?