AF due May 14th, spotting 3 days early

I'm not exactly sure when I ovulated. However I am not supposed to start my period until the 14th. I'm usually 28 day cycle. However I started spotting today. If this is the start of my period then it would be the shortest cycle I have ever had at 26 days.  Has anyone had implantation bleeding 3 days before a missed period? I may just be getting my hopes up but I would love any input any one has!  Baby dust to all!!!