chapman we are in exactly the same boat! I cracked and did a test this morning, BFN, but AF still hasn't shown up. This evening feeling a bit tummy-achey, but don't think it's cramps, think I just ate my massive dinner too fast 
Further complicating matters is the issue of my shorter cycle this month...maybe I haven't ovd yet after all. But I've had consistently high temps for 12 days, and that only ever happens immediately before AF arrives (sometimes I'll get a day or 2 of high temps and think I've ovd, but then it goes back to normal and nothing happens for ages. Any time it stays up consistently, AF arrives, so I assume that means I've ovd, since it's v rare to get AF without ov).
So, either I am pg and just not showing on test yet, or I didn't ov and just need to turn my radiators down
or I did ov, didn't conceive and AF is just taunting me.
Am seriously considering wearing white knickers every day just to see if I can tempt her into action...! And if she doesn't turn up I'll be retesting on maybe Friday.
FX for BoBo, shan, chapman and anyone else testing over the next couple of days...surely it's time for at least one BFP! x