tmi with pic um confused need help please

well I suppose to start my cycle on the 13 but nothing so glow put me down for the 20 nothing I had a one day cycle June 15 that was my first cycle since I got off depot shot in Dec of last year so the twenty I had sex so blood then it was gone yesterday morning woke up wipe blood but never on pad this morning the same but never on pad just when I wipe now nothing could this be my cycle trying to come or implantation bleeding cause this blood not coming out