How to reconnect with someone?

So I met a girl a few months ago and we spent a whole day chatting/flirting and she asked for my number. Then I admit I didn't do anything after that because I was pretty shy. A few weeks ago, she started a conversation on Facebook but then the next week when I started one, there was no reply at all. I'm pretty sure that she likes/liked me but I'm kind of confused and it's been plenty long enough for her to forget about me.

How can I reconnect with her (if you think that's a good idea anyway)?