12/13 dpo ??

12/13dpo AM. small bright red spot of blood on tissue. Again a bit bigger at 5pm same day. That's it. Period due tomor-5 days (days 27 to 32) implantation? Cant be that's too late for that isnt it? Bfn today. Also on Clomid so could be that..... thoughts and opinions would be grateful. Thanks