No, your username doesn't say "14-year-old", it screams "15/16-year-old", because I immediately assumed you were born in the year 1995. Imagine my confusion when you stated that you're turning 17.
I thought it was a typo at first, and you meant to say you were turning
16. But now I know that you are, in fact, nearly 17!
Usernames generally don't have any effect on my choice of mod, unless they're really over-the-top, which yours isn't. It merely implies that you're a year younger than you actually are, which makes next to no difference either way. So no, your username wouldn't make me not want to download your mod, and I don't think any sensible person would skip over your mods based solely on your username.