<human>: After lurking on here for ages, it's the first time I've felt the need to post. Yay!

So, I met this girl on OkCupid and we've been talking for a few weeks on both OKC and via text. We finally met in RL yesterday, and I honestly thought we hit it off. She was displaying a lot of the typical signs of attraction (hair tossing, eye contact, close proximity, touch, etc), and we had a lot in common. We didn't go very far physically (just making out), as I sort of wanted to convey that I wasn't just looking for sex.

So, anyway, we go our separate ways, but make plans to meet up tonight at a show at our school. I shoot her a message at around Noon to see if things were still on, and she messages me back saying that she's sorry and she can't come anymore because she's seeing a movie with a friend.

So, I'm confused (and probably overthinking). Should I take her reply as an indication that she's still interested but just tonight wouldn't work out? Or is this supposed to be a message to me that she's not interested? In which case I'm very confused because it seemed to me like she was very interested last night.

Anyway, if it is genuinely a rejection (as the pessimistic part of my brain is telling me), then it would mark roughly the fourth time this has happened in the last year where I met someone and they seemed interested, but never followed up. I'm not sure what I'm doing wrong.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: Went on a date with a girl, thought we hit it off, but she suddenly seems distant. Where to go from here?