OPK confusion... HCG negative please need some advice

Danielle
Right ok... before I go absolutely potty! 
Here's why I'm banging my head against a brick wall..
So AF was due last Sunday, I'm 7 days late now for AF.. 
usually each cycle I have I get sore breasts a few weeks before AF is due to arrive, Possibly an ovulation sign? But not this month!  I don't know anyway.. enough about the boob situation that's not what I'm bothered about... what I'm really baffled about is the fact that I had an ovulation test just a little darker than this one around the 18th October since being late I've been having lower tugging aching in abdomen..& lower back aches.. 
I feel when I'm about to come on... it's been like this for the whole week now.. 
even though the last time in October we had BD was the 10th.. due to a busy schedule..
So by now even if I had OV'd early retrospectively I would have a positive test by now.. 
I just don't know what to think.. I've gone through about 10 HCG tests (the dip stick kind) I think they are clinical guard make.. not even a smudge of a line on any of them.. all tested with FMU.. just to rule out that I'm not a pysycotic ttc'er..
I just tested again this afternoon but in the process took an OPK and thought what the hell it won't hurt.. and this is the result.. before you say it.. I know the lines not as dark as the control line however this is the darkest I've ever got.. since I've used them before (I will do another about 5.30pm) 
Do u think ovulation has maybe been delayed in my cycle? And I've either just ovulated.. or my surge is coming very soon... hence no period..
I'm so confused by it all..