This is one thing we don't have to worry about.
But yeh, it's common as hell for girls to lie to Chad to get fucked, and then turn around and call it rape to get pity/not-being-called-a-whore. I've seen this scenario in many movies and tv shows. It's at the end of Raging Bull, and there was that Family Guy episode about it.
If I ever get involved with a girl, I'm going to secretly record everything as evidence that I didn't rape anybody. But now, apparently, "yes means no." (see Loius CK scandal)