<human>: This is kind of a continuation of  Not sure if dating is the right flair for this but I think it fits because it is a relatively "new" relationship.

Basically, I've been hanging out with this female friend every once in a while, we'd probably hang out every two or three weeks (just the two of us usually). I'd say she was the one to ask to hang out maybe 60-70% of the time.

In general things were pretty platonic, although as I mentioned in the linked post, there was one time that she was complaining about being lonely and all her friends being in relationships. This was a few months ago and she hadn't really mentioned it again after I kind of skirted the topic. 

About a month ago she went on 2-3 week trip to another country, I didn't really talk to her during this period of time because I figured she'd be busy or might not have service anyway. When she came back, she started acting kind of... frosty, I guess. 

She pretty much stopped communicating with me on Facebook. I sent her a message asking how the trip went, she finally replied a few days later with a pretty succinct response. I asked her a few questions, and it'd take her a few days to respond while before she would usually respond within a few hours of seeing a message. The last comment I sent her didn't prompt a response at all, and it's been about a week since then.

What should I do? Am I reading too much into this? I know this sounds pretty petty, but I did enjoy talking to her and I thought we were friends, so I'm kind of worried that I did something to screw it up. Could it possibly be the timing with Valentine's day coming up?

Can you summarize the given text in a few sentences?
<bot>: Female friend stops talking to me after a long vacation, not sure why. Worried that I might be doing something wrong to screw up our friendship.