I was going to say the exact same thing as Patti and Nikki. Even when everything is timed *perfectly* you only have a 15-25% chance of conceiving on each cycle, and with your tube removed it may be a bit lower for you. However, looking at your charts there are none where I would say your BDing was timed perfectly, and only two where it was "pretty good". So I think it could be nothing more than bad timing, which is great because that is the easiest thing to fix!
I agree with Nikki's recommendation - you are lucky because your ovulation is really regular, so I would get going today and keep it up everyday if you can until CD 15-16 at which point you will most likely see your temp shift.
GOOD LUCK!!!