Cat pee around my house.

I have a female cat, she's about 7 months old. I can smell her pee on my carpet and I'm pretty sure she's peeing on it. Each time I find a smell, its never wet. It's always dry but I know it's there because it's pretty strong. She doenst only pee there, she pees in different places, and I cannot seem to understand why or how to stop it. Her litter box is always clean and big enough for her to do her business. How can I stop this? And how can I remove cat pee from my carpet?