Implantation Bleeding?

Hey everyone, I'm new to this. I'm slightly confused so just wanted some other opinions. So myself and my partner have been trying for a baby. We are coming up on 4 months now, which I know isn't long but we are both young and all members of our family have got pregnant within a month of trying, but no luck for us so far. 

we have been using the CB home ovulation kit and I got a positive on July 28th. My period isn't due until the 25th of this month but since the night before last I have had some bleeding. It started off to just be a very very light pink and then went to a brownish colour with some bright red and now back to Brown. I usually get the worst periods with clotting and very dark red in colour, which I haven't got at all this time and it's over 10 days before I'm due. (So sorry about all the detail) I also am usually in bed for at least 24 hours with the pain and I've only felt a little twinge this morning and nothing else. 

Could this be implantation bleeding or is it just my period coming very early? I'm just so scared to get my hopes up 😔