This guy and I had oral sex yesterday but I know he had rubbed up against me at one point. Today I got my period 4 days early (I'm not always regular) and it's not light or look like discharge or anything but I'm worried if this could be implantation blood, but I also read that it's not possible to have that until 6 days after so I'm just wondering if it really is my period I guess I'm just nervous considering this is my first time doing anything like this.