Is she not interested anymore all a sudden?

I met her online

like after we chatted about an hour, she suggested we meetup before we hang with our friends
so we met at a bar. We had a great conversation. Very attractive and successful. A little older than me. I have about a semester left in college

So right when we were about to leave she said, "Yeah, give me a call and we can hang again"
I said "totally"

I texted her after and said" you seem really cool"
She said "thanks you too"

later that night I said, want to hang tomorrow? If you don't work? On her iphone it said she read it, then next day I said, "Just wondering, haha"

still nothing from her, and I saw her log on to the dating site several times. Does that mean I should back off?
:/

Super confusing

Slow down… Don't rush it