https://img21.imageshack.us/img21/8050/image1l.png
OK just wanted to give an alternative opinion here...I have read that you should count the darkest part of the line against the control, no matter how thick it is. So the one on the bottom looks darker and I would count it as a positive. If your temp has already risen are you suspecting that you have already O'd?
EDIT: From peeonastick.com:
13. My test line looks "half positive"-- only one side of the line is dark. What does it mean? Most of the time, OPK results are easy to read; the "result" line is one uniform color/darkness. Sometimes, however, you may get a result that looks "half positive," like this:
https://peeonastick.com/halfpos.jpg
"result" line on left
"control" line on right
When this happened to me, I contacted the distributor (in this case, BabyWishes.org)-- I even e-mailed them the above photo. I was told that the darkest part of the "result" line should be compared with the test line, and that this applies to all brands of OPK's.
This month I purchased some Answer brand OPK's, which I had never personally used before. After my LH surge appeared to last 6 days (going by the above rule of thumb), I made the unsettling discovery that my tap water was also ovulating. So I called Answer's 800# and asked the same question. This time I was told that the dark part of the line must be at least 50% of the total width to be considered positive. Going by THAT, the picture above would be considered negative. (And, in retrospect, my LH surge actually lasted a common 2 days-- and my kitchen faucet is not currently fertile.)
So, it appears that my information from BabyWishes was incorrect; it does, in fact, depend on the brand of OPK.
