The link for your chart still isn't working.

I'm not an expert on charting, but I will try to give you the best advice I can.
Make sure you're taking your temp at the same time every morning first thing, after at least four hours of solid sleep. Some people do have erratic temps, and they can be caused by anything from the temperature of the room, illness, having a bad night's sleep, etc.
OPK's detect LH, which is always in your system in small amounts. Sometimes an OPK can show faint lines (I actually always have a very faint line when I test). They can even start to get darker, but then go back to light or nonexistent due to LH fluctuations or the concentration of the urine. The best thing to do is just keep testing until you see a positive result. The first time I got a dark (but still not equal to the control) line, I tested again later that day and got a positive.
Hope that helped a little.