Strange Google Analytics mystery

I am trying to understand something and I need help please.

Several years ago I began a www.ads-software.com blog by buying a theme (from Themify) and installing it together with a normal HTML website. I had a Google Analytics account and I set things up to track for the whole website (HTML + WordPress) and to track the blog alone.

To track on the HTML, I wrote a small includes file which loads in the header of every HTML page. I cannot remember how I put the Google Analytics code into the blog. But both parts of the site are recording visits.

Now I want to check the GA code in the blog and I cannot find it anywhere. And I want to understand what is happening.

1. I don’t have a GA plugin. The only plugin that comes close is Google XML Sitemaps, but it doesn’t do tracking code.
2. I haven’t inserted the tracking code into any obvious file such as header.php or footer.php.
3. I have used the terminal (I use a Mac) to search for my tracking ID and it doesn’t appear in any file I have loaded up to the server.

I cannot see how I can get visit results from Google without the tracking code and ID.

So can anyone help me please – is there some way that aGA can be installed in WordPress that I used then but can’t work out now?

Thanks.