Is it normal that every time my gf and i kiss, i kinda get turned on?

It's been almost six months since we started dating, and everytime we kiss, even a simple or little kiss, kinda turns me on? Except a smack kiss though. I'm worried that what if I just want to have sex with her and I don't really love her? Because my body, or I, rather, react that way even with just a kiss.