they do not have spurs, you are correct that it is only veiled chams.
Do you know how old it is? The bulge of the male hemipene can show as early as a few months. If you go here
and look at the "boy?" photos you can see the blue in Cy's cheeks and the little bulge at the base of his tail (sorry I can't include photos, webshots doesn't hyperlink). He was three months old. He is a Nosy Be so not sure about the coloration (showing blue in cheeks) but if yours is much more than a few months, and a male, I would think the hemipene would be noticeable. If you can post pics of that area I am sure someone can help you sex him/her.