Indexed and then cant be found

Is this what is meant by the sand box?

[seamus]

I've recently uploaded a new site and started contacting similar sites for links. I got a few inbound links and so started getting traffic (not much)

My new site appeared on google after only a few weeks

But now it can’t be found on google, not even when I search using the url.

Is this what is meant by the sandbox? How long before it reappears?

Or could something else have happened?