Someone please explain..

So I usually have a 29/30 day cycle each month.. I’ve been using OPK and I ovulated on the 26th Of May which means it would of been Cycle day 13.. with having the cycle I have I understand that you ovulate a different times each month.. but isn’t that early for my cycle length?? I received a faint positive HPT at 10DPO, 11DPO a positive digital and today at 12DPO my FRER is dark and I even took a cheapy and it’s there. Now my period isn’t due until the 12th or 13th of this month which puts me at 5/6 days waiting still?? How is this possible? How did I get such a dark line so early but still have to wait on my AF..