I was in the same boat as you before the Camp Pendleton Tri (same distance too). I went for an easy ride the week prior as well to see how I felt. And although I was ok, I felt worse after the ride than during. Coughing a lot! So, I decided just to rest and do nothing but rest and sleep a lot prior to the race. I too, was nervous about the lack of training just a little prior to my big race. The rest however, paid off, I did the race (not a great finish), but I finished and was happy about that.

Good Luck!