Why do I have a bed icon next to my charging level percentage on my I phone 6s?

See the information in Use Focus on your iPhone, iPad, or iPod touch - Apple Support including the following:

When you set a Focus, the icon appears in the status bar and on your Lock Screen, and your status is automatically displayed in the Messages app. 

I do not have any Focus active and I still have the bed icon in my header. I found that if I turn a focus on and then turn it off, the bed icon will clear.