I leave the iBooks app open in the background on my iPhone sometimes does that count towards my reading time?

I leave the iBooks app open in the background on my iPhone sometimes does that count towards my reading time? Im worried that leaving the app open in the background affects how long I’ve been reading the book when I really just do it out of convenience so when I have a free moment when I go to check and see what I was doing before I see that I was reading and can continue