Sorry...just need to get something off my chest...!
Am desperately ttc (cycle 8), and have religiously been plotting my periods using various apps, using opks and have just downloaded another fertility app so I can plot my temps...
I even went as far as to dtd EVERY night for 8 days in a row last month, so please forgive my frustration!
Anyway, all of the reading I've done suggests that, obviously, you need to know exactly when you ovulate to maximise chances of conception! Even better, there's a formula you can use to calculate thus date that uses the length of your luteal phase! Brilliant I think!! 
So, the "magic day" of ovulation = length of cycle - length of luteal phase! Easy peasy...!?!?!
Nooo!!! The length of my luteal phase is the number of days from ovulation until my next period... IF I KNEW WHEN MY DAY OF OVULATION WAS I WOULDN'T BE DOING THIS SODDING EQUATION IN THE FIRST PLACE!!!!! 




Sorry...I feel so much better after that...
Anyone else getting equally frustrated with it all??
Ta!
P.s... Wtf is this icon
supposed to be?????