IMPLANTATION OR O'ing LATE?

Ashlee
Does anybody have experience with ovulating late? I have a 26 day cycle, period lasts 5 days and last month for the first time I took an ovulation test and got a smiley face on CD 12. Well on my ovia app I use every month it gave me a OD of 11/12th this month. 
Now here's my question.. We DTD Friday and yesterday afternoon I had mild AF like cramping for about 2.5 hours then nothing since. It would only be 4-3 dpo depending so it's too   Early for implantation right? Did I just O late? I DTD again last night just in case but I'm feeling really confused now. 
AF was from aug 31-sept 4th. Suppose to see AF again on the 26thz