Prettyuch that I said something wrong, or I'm over reacting and she is actually busy,. It's really hard to gauge that sort of thing, best thing to do is leave it. If she responds to you later than its fine, if she contacts me as like she was starting a fresh new set of texts, she wasn't listening, or hated the convo.
It depends on how well we know each other and some other context. If we just met recently and it already happens often, I usually assume it means she isn't interested in knowing each other. If we've been friends, then I assume she's just busy or didn't feel interested in that conversation and we'll talk later about other stuff.
"well she´s not interested, so fuck her". because that´s how like every girl on the dating site does it. they just stop talking to you. at first it irritated me but now i´m just like "ok fuck you bitch. your loss."