Is it on both sides of your thighs? That would point to jock itch more so than herpes, or another fungal infection, though herpes can be on both sides - it's just more unusual.
Herpes really shouldn't be visually diagnosed. It's way too similar in appearance to fungal infections and other things to rely on a visual.
Did the doctor you saw the other day do a culture or anything on it?
When you get the results back, let us know. My guess is that he did an IgM test. In theory, that test is supposed to look for new infections. It's just terribly unreliable, and shouldn't be done on anyone but newborns. My own IgM was negative when it should have been positive, and positive when it should have been negative.
If he did an IgG test, it can take up to 4 months to show positive on that.
We'll figure it out when you get the results back.