Have you measured it? No really. It may just be your perception of things, like an optical illusion. The only other thing I'm aware of is that weight loss can make it look bigger.
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Now that you're done laughing, fat deposits in that part of your body (I mean your groin, not your belly) and can obscure it. As you lose fat deposits, it may appear larger without actually being bigger.
As for the hormone levels, males physically develop until they're 25, often hitting a second puberty in their late teens early 20s. It could very well be that's what's happening to you. Its not going to hurt to have your levels checked.
If its any consolation, remember that penis length is a major determining factor in your vaginal depth post-op.
