forget BFP on pregnancy tests, I can't get one on OPK tests...

Chelsea
Just a short vent and maybe someone has some advice ....
Rewind to March... I stopped taking birth control at the end of March.
Since then my husband and I have used no birth control.
We then started charting BBT and CM as part of learning NFP but with hopes of conceiving. Each month my peak day is showing around cycle day 20.
I know that this really isn't that long ago and many of you have been trying much longer (I commend you, this sucks!). 
in July I started taking ovulation tests. In July on Day 19 or 20 I got a smiley face... Yay!! 
In both August and September I have gotten no smiley face at all, just a blank circle. 
Does this mean I'm not ovulating? Not enough raise to show in the test? 
My BBT has also been a bit off the last few months and not as easy to read in terms of which phase I am in.  
Any thoughts or similar experiences? I would love any insight!