Ugly mystery letters appear after url has loaded

I put in this url: https://gohproductions.org/GOHwordpress/ (I am working on making this site)

Once it loads it has an ugly addition like #.U0WD5uZdXd5 at the end. So: https://gohproductions.org/GOHwordpress/#.U0WD5uZdXd5

Does anyone know what causes this and/or how I get rid of this?

This just started happening a few days ago–I think. Or maybe I just started noticing it a few days ago. I had installed several new calendar plug-ins and thought maybe that started it, but after deactivating the plug-ins, it’s still there.

Thanks.