Had the EXACT same scenario a few months back and made the mistake of NOT closing the deal. Yes, you read that right. In hindsight, it was an error on my part to go heavy on the first date and then pull it back on the second. We ended up at my place the first night and things got wild. The second date, we ended up again at my place but I didn't seal the deal.. when she randomly said "i should get going" and then left rather awkwardly, I knew something was off....
My view is that she was expecting to bang on the second date.. when I didn't follow through, because i really liked her, it threw her off and she likely thought of me as less aggressive/masculine/all those good things girls like.
So my suggestion : Either go full speed ahead and go as far as she's clearly looking to go.... OR explain that you like her and want to take it slow as a result. If you're like me and slow things down WITHOUT EXPLAINING that's what you're doing, you look wimpo and the girl will lose interest.