To be honest, if you're dating exclusively, you're not even in her 10%. Because women aren't even interested in 1 in 10 men: it's more like 1 in 50. You're in her 0.02%. You've absolutely scored. Worrying about whether she likes someone else, while understandable, is an unlikely thing to have to face: unless she's mentioned an ex or rebounding, women typically select a romantic partners they want, rather than to fill a sexual need impermanently.