Could reading advanced books do more harm than good for my 5 yo?

We have always been big readers in my house. When I was pregnant I would read whatever I was reading at the time out loud and for awhile after he was born. When he started actually paying attention I switched to kids and poetry books... well now he is 5 and seems bored with the picture/kiddy books. He loves scary everything so of course he picked out some Goosebumps books from the library. I read a few chapters every night and he loves it but I can’t help but wonder if I’m doing more harm than good.. he swears he isn’t scared and asks every night to read it.