Help? Think I'm pregnant !

So ... I did not come on here to recieve negative comments about anything I'm just simply here for advice . So here goes , so I ovulated around September 17-23 22nd being my ovulation day according to one period calendar another one says I ovulated the 22nd of September - the 27th . I had unprotected sex the 26th of September . I'm not sure when I ovulated since it's different but my expected period was October 6th and it has been 3 days late . But today like 15 minutes ago I went to the bathroom and I noticed dark non looking period blood more like a discharge . I'm wondering if it's implantation bleeding ? Do you ladies think I'm pregnant ? I deffinately don't think this is my period . Feedback would be appreciated thank you !