Random Spotting

Hey ladies! Let's get right to the point. My boyfriend has pretty much been ejaculating in me for the last two months. I want a baby but the sex has been spontaneous on days I'm not even ovulating so we're obviously not pressing the issue. If it happens it happens type of thing. I already had my period the beginning of this month. I'm also not on birth control I've been normal. All of a sudden after sex and ejaculation today I go to the bathroom and theres blood coming out of me like period blood mixed with his sperm but this is wierd to me because I don't have cramps or anything. Any idea if this is an early sign of pregnancy? I thought implantation bleeding occurs right before your period and I don't come on again until the 27th.