The thing about the test is that it is compared each time to a control. If the control that is run on that particular day is a little higher than the last time, all the values are going to be a little higher. You are still certainly negative at 13 weeks. And no, I would not say you are trending upwards. I think if you were infected, these values would be quite a bit higher at 13 weeks post possible infection. The variation in the index values is completely and totally normal.
Are you going to test again at 16 weeks?
You should also know that the test for HSV 1 misses about 1-2 out of 10 infections, but 56% of the population has HSV 1, between the ages of 14 and 49, so it would not be surprising if you were infected with HSV 1.
Terri