Hmmm. I have some catching up to do after the man flu.
Did 2.85 miles this morning at a glacial pace and with a heart rate about 10 bpm above where it should be, but I'm hoping that's down to temporary lack of fitness while I get back into things rather than a sign that the bug is still present.
I'm in a similar situation, other than my half is a week later and it will be something like my 50th. And at death's door with man flu right now.
From what you say, you're doing the right thing. The training you've done until now is in the bank, and it takes two to three weeks for the training benefit to filter through anyway. Looks like you've done plenty to be ready on the 15th. With two weeks to go, if you're not ready now you never will be.
So you need to expel the last vestiges of the bug. Do as you're doing - test it out with a bit of gentle jogging, gradually take it up to something a little longer or faster in the coming week if it feels good but DON'T OVERDO IT!!! and be sure to listen to your body. Avoid injury or relapse.
You might be surprised how it goes on the day. I've had races when I've just recovered from a cold or flu but done better than expected.