Help with cycle figuring

Crystal
1st day of last cycle was 5/27 and they average about 31 days, according to the 2 apps I use i, I should have ovulated on 6/19 or 6/20. And started AF around 7/2 to 7/4...still no AF and BFN on test today. If everything is normal I should be 17-18 DPO, right? How long should I wait to test again?